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GJM
11-28-2020, 08:59 AM
SoCalDep and rca90gsx via pm provided me excellent information on screws, and my upcoming New Year’s resolution is to regularly replace optic screws. One thing that held me back is paying $10 or $15 for two screws, and not having a bunch of them around. I thought it might be helpful to post up the exact part number for common installations and a link where screws can be ordered in bulk.

Per SoCal Dep, the link for the CORE SRO/RMR/Holosun 6-32 1/2 long Torx screws is 94414A148 and they are $9.28 per 50 at McMaster.com. I believe these should work with the OEM and C&H plates.

It would be great if we could populate a list in this thread, like below:

CORE SRO/RMR/Holosun C&H plate 6-32 by 1/2 long, Torx 15 part number at McMaster.com — 94414A148


Anyone have the info for direct milled and MOS Glock installations?

SoCalDep
11-28-2020, 01:32 PM
Here are the screws I use which are available from McMaster-Carr (mcmaster.com):

6-32 x 3/8” (RMR – MOS Plate) - Part # 94414A146
6-32 x ½” (RMR/Holo – S&W CORE) - Part #94414A148
6-32 x 5/16” (Holosun – MOS Plate) - Part #94414A341
M3 x 0.50mm x 6mm (MOS Plate – MOS Slide) - Part #94414A712

These are black oxide finished alloy steel. If you live/work in an area where rust is a big issue then search for the same dimension screws in stainless on their web site and you'll be good.

Make sure all surfaces (threads in plates, slide, etc.) and screws are degreased and use decent thread locker. I prefer Loctite 248 but have had success with Vibratite when applied EXACTLY as recommended by C&H Precision.

GJM
11-28-2020, 01:37 PM
Here are the screws I use which are available from McMaster-Carr (mcmaster.com):

6-32 x 3/8” (RMR – MOS Plate) - Part # 94414A146
6-32 x ½” (RMR/Holo – S&W CORE) - Part #94414A148
6-32 x 5/16” (Holosun – MOS Plate) - Part #94414A341
M3 x 0.50mm x 6mm (MOS Plate – MOS Slide) - Part #94414A712

These are black oxide finished alloy steel. If you live/work in an area where rust is a big issue then search for the same dimension screws in stainless on their web site and you'll be good.

Make sure all surfaces (threads in plates, slide, etc.) and screws are degreased and use decent thread locker. I prefer Loctite 248 but have had success with Vibratite when applied EXACTLY as recommended by C&H Precision.

Awesome add!

Screws are a really important part of the mounting equation, and having the proper size, Torx head, and replacements are a key to keeping the dot secure. Let’s fill in some more part numbers for different applications and get this stickied!

Whirlwind06
11-28-2020, 01:45 PM
I bought this kit a while ago
https://chpws.com/product/red-dot-torque-kit
Seems to work pretty good

tlong17
11-28-2020, 02:36 PM
I have used these #4-40 pitch 5/16" length screws for

LTT RDO + Holosun (507/407c & 508T)
Glock direct milled by CHPWS with Zev Posts + Holosun (507/407c & 508T)

Part # 94414A322
https://www.mcmaster.com/94414A322/

ranger
11-28-2020, 06:01 PM
Slight thread drift. I need some 6-48 screws to mount a 20 MOA rail to a Bergara HMR (Remington SA mount). Anyone got the part number for those? Thanks

SoCalDep
11-28-2020, 07:21 PM
I bought this kit a while ago
https://chpws.com/product/red-dot-torque-kit
Seems to work pretty good

That's a great kit, especially if you're exclusively using the C&H Precision plates. If you're using other plates and other torque specs then an adjustable wrench might be better. I have a couple Wheeler FAT wrenches and they're alright, especially if on a budjet. The Capri CP21075 is a nice 1lb increment adjustable torque wrench and the Vortex version is simply a re-branded Capri at a cheaper price, especially if you have a law enforcement discount like expertvoice.

I'm probably going to pick up a Fix it Sticks set (like what is included with the C&H set) just to try them out because they'd be cool for a really compact kit as well.

SoCalDep
11-28-2020, 07:23 PM
Slight thread drift. I need some 6-48 screws to mount a 20 MOA rail to a Bergara HMR (Remington SA mount). Anyone got the part number for those? Thanks

Take a look at mcmaster.com... there's a good chance they'll have what you're looking for.

GJM
11-28-2020, 07:37 PM
Once we get all the info into this thread, I will organize it or start a new one so we keep the info handy as a resource.

I am thinking Torx 15 is ideal, but is there an argument for something else?

tlong17
11-28-2020, 11:38 PM
Once we get all the info into this thread, I will organize it or start a new one so we keep the info handy as a resource.

I am thinking Torx 15 is ideal, but is there an argument for something else?

I would agree with 15 being ideal. It appears that for certain thread pitches, like 4-40 for example, that is not an option. Likely due to the smaller size of the thread and screw head.

Erick Gelhaus
11-29-2020, 01:01 AM
GJM & SoCalDep thanks to both of you for the info.


I bought this kit a while ago
https://chpws.com/product/red-dot-torque-kit
Seems to work pretty good

I bought a full kit, not just the torque head, from Fix-It-Sticks.

MD7305
11-29-2020, 02:41 AM
Thanks for the information. I had wondered where to get some extra fasteners and you guys answered that question. Those 50 fasteners should last me, I hope.

HCM
11-29-2020, 02:44 AM
That's a great kit, especially if you're exclusively using the C&H Precision plates. If you're using other plates and other torque specs then an adjustable wrench might be better. I have a couple Wheeler FAT wrenches and they're alright, especially if on a budjet. The Capri CP21075 is a nice 1lb increment adjustable torque wrench and the Vortex version is simply a re-branded Capri at a cheaper price, especially if you have a law enforcement discount like expertvoice.

I'm probably going to pick up a Fix it Sticks set (like what is included with the C&H set) just to try them out because they'd be cool for a really compact kit as well.

https://www.amazon.com/WIHA-28595-53-PC-TORQUE-CONTROL-SCREWDRIVER/dp/B000T9W54G?pd_rd_w=SFeMr&pf_rd_p=4eebd874-436f-4f05-a794-09646834b2dd&pf_rd_r=KWPEW01KXZWZ96X34DKX&pd_rd_r=7774eeb7-ba97-4d61-9842-c16311f327d9&pd_rd_wg=jlSQc&pd_rd_i=B000T9W54G&ref_=pd_bap_m_rp_76_sc

I bought this Whia kit at the recommendation of NickDrak.

It’s proved useful for a range of gun and optic related tasks.

SoCalDep
11-29-2020, 02:52 AM
https://www.amazon.com/WIHA-28595-53-PC-TORQUE-CONTROL-SCREWDRIVER/dp/B000T9W54G?pd_rd_w=SFeMr&pf_rd_p=4eebd874-436f-4f05-a794-09646834b2dd&pf_rd_r=KWPEW01KXZWZ96X34DKX&pd_rd_r=7774eeb7-ba97-4d61-9842-c16311f327d9&pd_rd_wg=jlSQc&pd_rd_i=B000T9W54G&ref_=pd_bap_m_rp_76_sc

I bought this Whia kit at the recommendation of NickDrak.

It’s proved useful for a range of gun and optic related tasks.

I’ve heard really good things about Wiha and I’ve bought a bunch of their bits. I bet they are at least as good as or better than what I’ve used.

SoCalDep
11-29-2020, 03:05 AM
Once we get all the info into this thread, I will organize it or start a new one so we keep the info handy as a resource.

I am thinking Torx 15 is ideal, but is there an argument for something else?

I think it depends on screw size. The M3 screws I referenced are (I think) IP10. I’m more about torx than size of torx.

Also.. at the end of the day I think it’s more about how one mounts than about the screws they use. Though I do hate hex... Boooo!

Archer1440
11-30-2020, 06:44 PM
For the RMR, I use the following McMaster-Carr screws for direct replacement of the factory screws after the first battery change. This is a very high-tensile strength, American made Torx/Torx-Plus part, and it comes at a very reasonable price.

https://www.mcmaster.com/94414A148/

Quantrill
11-30-2020, 07:50 PM
Anybody got a source for 6-40 x 1/2” with a Torx head?

My L&M RMR cut came with hex/ Allen head. I’d really like to change to torx

Mirolynmonbro
12-01-2020, 12:23 PM
Good thread idea. I need to figure out which ones I need for my primary machine P09 and P07 / Holosun slides

OlongJohnson
12-01-2020, 02:01 PM
Anybody got a source for 6-40 x 1/2” with a Torx head?

My L&M RMR cut came with hex/ Allen head. I’d really like to change to torx

Don't know what head form you need, but something like this might be close. Play around with the filters on this site.

https://www.mscdirect.com/product/details/03042678

GJM
12-08-2020, 06:11 PM
At $8/screw retail, this is several thousand dollars of screws, bought for about $40 in bulk.

64362

SoCalDep
12-08-2020, 11:30 PM
At $8/screw retail, this is several thousand dollars of screws, bought for about $40 in bulk.

64362

Yea buddy!

wilco423
12-08-2020, 11:50 PM
Anybody got a source for 6-40 x 1/2” with a Torx head?

My L&M RMR cut came with hex/ Allen head. I’d really like to change to torx

I tried a bunch of 6-40s for Sig PRO slides, and found these to be the best overall (scroll down for the right size).

https://www.brownells.com/gunsmith-tools-supplies/small-hardware/metal-screws/torx-head-scope-ring-base-screw-kit-prod41830.aspx

OlongJohnson
12-09-2020, 07:24 AM
At $8/screw retail, this is several thousand dollars of screws, bought for about $40 in bulk.

64362

Or you could say it's $40 worth of screws, which will be marked up to several thousand dollars if you buy them the wrong way.

Quantrill
12-09-2020, 09:15 AM
I tried a bunch of 6-40s for Sig PRO slides, and found these to be the best overall (scroll down for the right size).

https://www.brownells.com/gunsmith-tools-supplies/small-hardware/metal-screws/torx-head-scope-ring-base-screw-kit-prod41830.aspx

Thanks for the info but what I need isn’t an option. I need a machine head screw, at least I think that’s what it’s called. I can find the right screw all day with hex drive. Torx drive in 1/2” length seems to be a unicorn.

MD7305
12-09-2020, 03:17 PM
You guys using the McMaster hardware, have you seen any trouble threading them? They are very tight on my M&P, and when I back them out there's noticable wear on the screw threads and a "ribbon" of material that I believe is from the screw itself. I've already sheared one in a slide, I'm a little wary of switching out my others. The hardware sent with my CHPWS plate does the same thing but the hardware from my Holosun and included from S&W threads easily and smoothly. Any ideas?

It looks like it's flattening or dulling the threads
64424

SoCalDep
12-11-2020, 01:23 AM
You guys using the McMaster hardware, have you seen any trouble threading them? They are very tight on my M&P, and when I back them out there's noticable wear on the screw threads and a "ribbon" of material that I believe is from the screw itself. I've already sheared one in a slide, I'm a little wary of switching out my others. The hardware sent with my CHPWS plate does the same thing but the hardware from my Holosun and included from S&W threads easily and smoothly. Any ideas?

It looks like it's flattening or dulling the threads
64424

What did you shear? A McMaster screw? Was it a hex or torx drive (or other screw)?

MD7305
12-11-2020, 01:33 AM
What did you shear? A McMaster screw? Was it a hex or torx drive (or other screw)?

Yes, it was a McMaster torx drive. They thread into my slide very tightly and leave wear on the threads of the screw to the point I'm leary of attempting to fully thread them in. I have two M2.0 compacts and it's the same situation with both. They become very tight before even coming close to even seating into my Holosun/CHPWS plate. Any ideas about what's attributing to this? After breaking one I'm very nervous about doing it again. The Holosun and S&W hardware threads into the slide without issue.

SoCalDep
12-11-2020, 01:59 AM
Yes, it was a McMaster torx drive. They thread into my slide very tightly and leave wear on the threads of the screw to the point I'm leary of attempting to fully thread them in. I have two M2.0 compacts and it's the same situation with both. They become very tight before even coming close to even seating into my Holosun/CHPWS plate. Any ideas about what's attributing to this? After breaking one I'm very nervous about doing it again. The Holosun and S&W hardware threads into the slide without issue.

How did it break? What did the screw look like. What part was left in the slide?

Was it during shooting or installation? Did you tighten to a specific torque spec?

I ask because if there is a problem I want to deal with it and make things better, but details matter. Wear happens with friction between metal parts. Friction can mean intolerance or tight tolerance. Friction helps things stay in place. Poor tolerance can increase wear, but torsion force (a tight screw that has lots of friction) dissipates quickly when that force is no longer applied... so it’s important to have as much detail as possible to diagnose a problem.

MD7305
12-11-2020, 02:46 AM
How did it break? What did the screw look like. What part was left in the slide?

Was it during shooting or installation? Did you tighten to a specific torque spec?

I ask because if there is a problem I want to deal with it and make things better, but details matter. Wear happens with friction between metal parts. Friction can mean intolerance or tight tolerance. Friction helps things stay in place. Poor tolerance can increase wear, but torsion force (a tight screw that has lots of friction) dissipates quickly when that force is no longer applied... so it’s important to have as much detail as possible to diagnose a problem.

It broke while I was installing my CHPWS plate along with the new McMaster hardware. The screw was about halfway threaded in, the screw head wasn't touching the Holosun yet. I noticed it was becoming tighter, at that point I should've stopped, but I continued tightening and it broke. I hadn't used my torque wrench at that point because the screw wasn't seated yet. That's totally my fault but I noticed that when threading the screws in my other slide there was flattening on the edge of the threads of the hardware. I was curious if that was normal or something you guys had experienced.

The first half of screw threads remain in the slide, with about 1/8" protruding from the top of the optic cut.

The hex hardware included with my CHPWS plate also was difficult to thread. Could the threads in my slides be out of spec? Could it be a tolerance stacking issue due to the slide apparently being finished after they were tapped/threaded? This is the case for both slides.

Archer1440
12-14-2020, 11:01 AM
Could the threads in my slides be out of spec? Could it be a tolerance stacking issue due to the slide apparently being finished after they were tapped/threaded? This is the case for both slides.

Hard to give a definitive answer without running a go/nogo gauge on the threads. Occam’ s razor says it’s probably a combination of finish and thread tolerance, but without data that is just an educated guess.

You could get thee to a gunsmith and have him gauge them, and if needed chase those threads with a tap.

Caballoflaco
12-14-2020, 12:38 PM
Yes, it was a McMaster torx drive. They thread into my slide very tightly and leave wear on the threads of the screw to the point I'm leary of attempting to fully thread them in. I have two M2.0 compacts and it's the same situation with both. They become very tight before even coming close to even seating into my Holosun/CHPWS plate. Any ideas about what's attributing to this? After breaking one I'm very nervous about doing it again. The Holosun and S&W hardware threads into the slide without issue.

My general rule of thumb when using new or replacement fastners is to first try them in the threads without any threadlocker. For small applications like this I want to be able to screw them into the threaded hole with a thumb and forefinger on the wrench making a movement not unlike playing a tiny violin. If everything fits good I’ll back it out apply thread locker etc and do the actual installment. (I spent 5 years wrenching on bicycles and stripping out threads on certain components could be a very expensive mistake)

I agree on seeing if you can get your screws and slide gauaged and possibly have the threads chased,

maximus83
12-14-2020, 12:47 PM
The hex hardware included with my CHPWS plate also was difficult to thread. Could the threads in my slides be out of spec? Could it be a tolerance stacking issue due to the slide apparently being finished after they were tapped/threaded? This is the case for both slides.

I have the M&P 2.0 compact as well and just ordered the CHPWS. So shortly, I'll find out if I can repro your issue.

* I haven't noticed, do we have anybody here who has installed the CHPWS with its own or other 3rd party screws and no issues, on the new optic-ready M&P M2.0 compact?
* You mentioned the out-of-spec option, another option is maybe the M2.0 compact has a different spec for its screws than the CORE?

maximus83
12-19-2020, 12:23 AM
It broke while I was installing my CHPWS plate along with the new McMaster hardware. The screw was about halfway threaded in, the screw head wasn't touching the Holosun yet. I noticed it was becoming tighter, at that point I should've stopped, but I continued tightening and it broke. I hadn't used my torque wrench at that point because the screw wasn't seated yet. That's totally my fault but I noticed that when threading the screws in my other slide there was flattening on the edge of the threads of the hardware. I was curious if that was normal or something you guys had experienced.

The first half of screw threads remain in the slide, with about 1/8" protruding from the top of the optic cut.

The hex hardware included with my CHPWS plate also was difficult to thread. Could the threads in my slides be out of spec? Could it be a tolerance stacking issue due to the slide apparently being finished after they were tapped/threaded? This is the case for both slides.

Got the CHPWS and mounted on the M&P M2 compact. Their hex screws were a little snug going in but not terrible. Backed them out to inspect; lower thread was polished shiny as you observed with a tiny shaving. Definitely there was tightness/friction on the threads, but not enough to be a showstopper. Seen threaded screws do this before when tight or right at the edge of the tolerances.

Added blue loctite and torqued down to 15 in/lb, went in fine. I'll get a pack of the McMaster screws as well to rate them.

rca90gsx
12-19-2020, 12:37 AM
2.0 compact, factory plate, 3rd party screws. Everything fit perfect. Cleaned slide really well, cleaned screws, test fit by hand, threaded in perfectly. Installed with loctite very easily.



I have the M&P 2.0 compact as well and just ordered the CHPWS. So shortly, I'll find out if I can repro your issue.

* I haven't noticed, do we have anybody here who has installed the CHPWS with its own or other 3rd party screws and no issues, on the new optic-ready M&P M2.0 compact?
* You mentioned the out-of-spec option, another option is maybe the M2.0 compact has a different spec for its screws than the CORE?

maximus83
12-19-2020, 12:49 AM
3rd party screws.

Which ones?

rca90gsx
12-19-2020, 12:58 AM
McmasterCarr 6-32x1/2" alloy steel Torx head. That is the longest to fit. The 9/16" length bottoms out just before tightening all the way down, i didn't want to file those to length.




Which ones?

maximus83
12-19-2020, 01:07 AM
Good to know, those were the ones I just ordered, hopefully they fit as well or better than CHPWS screws.

SoCalDep
12-21-2020, 12:02 PM
Received another McMaster-Carr order on Friday. I ordered some of the 6-32 x 5/16" (Holosun - MOS) alloy steel screws and tested them on an MOS plate. The 5/16" screws flushed up perfectly to the bottom of the MOS plate - maximum thread engagement without any protrusion through the bottom. I'm happy with that.

I also ordered M3-0.5 x 10mm alloy steel screws (part # 94414A714) for my Sig P365XL and Holosun 507K. I wasn't sure since I was going by the Romeo Zero instructions which don't list screw length, but 10mm matched the length of the screws that came with the Holosun perfectly. I test fit and (re)mounted the 507K with the new screws.

I'm (based on Caballoflaco's excellent post above) revising my mounting procedure to include pre-fitting the screws without threadlocker to ensure they fit correctly. Therefore, my new steps are:

1. Make sure pistol is empty
2. Field strip
3. Prepare all surfaces (slide, plates, screws, threads) by de-greasing.
4. Test-fit screws in threads to ensure proper fit.
5. Apply threadlocker to screws (preferably Loctite 248)
6. Thread the screws until resistance is felt and then alternate slight increases in torque for each screw using a torque wrench to the lowest torque specification of any of the interacting components.
7. Place indicator marks on the screws/plate or screws/optic with a toothpick to make it easier to identify a loose screw.

After a near disaster yesterday and a couple weeks ago with a paint-pen, I will no longer apply the paint directly from the pen. I'll use a toothpick now just like I do with Torque-Seal. I apply the paint to one of the alcohol prep-pad wrappers that I've used and then use the toothpick. I'd be tempted to just get a couple small jars of Testers paint, but having to stir them may be more of a pain compared to shaking the paint pen.

tlong17
12-21-2020, 08:44 PM
After a near disaster yesterday and a couple weeks ago with a paint-pen, I will no longer apply the paint directly from the pen. I'll use a toothpick now just like I do with Torque-Seal. I apply the paint to one of the alcohol prep-pad wrappers that I've used and then use the toothpick. I'd be tempted to just get a couple small jars of Testers paint, but having to stir them may be more of a pain compared to shaking the paint pen.

I’m glad you mentioned this lol. I had a disaster of my own attempting to use the paint pen to apply directly to screws. Not fun cleaning it out of the optic and slide. Not uncleanable but not fun! Toothpick works much better for me too.

maximus83
12-23-2020, 12:03 AM
Now I'm having an issue as well. Hardware with the CHPWS stripped one screw trying to remove to replace with the new screws.

ETA got the stripped hex out using oversized torx trick. But the McMaster screws I'm having the same issue as MD7305. They seem to be at the edge of the tolerance for the holes drilled in my compact; they don't feel right and are too tight to force. These screws aren't going to work in this gun.

MD7305
12-23-2020, 12:19 AM
I got my slide back from my gunsmith today and he was able to successfully remove the sheared screw. He said due to the McMaster hardware being heat treated it was pretty difficult to extract. I asked him to chase all of the threads and now the hardware threads smoothly and easily, no hint of resistance.

I'm probably going to take my second gun to the gunsmith and have him chase those threads as well. I see a big advantage using the McMaster hardware due to the added length and torx head so I'm glad to get this sorted out.

md8232
04-17-2021, 06:28 PM
Received another McMaster-Carr order on Friday. I ordered some of the 6-32 x 5/16" (Holosun - MOS) alloy steel screws and tested them on an MOS plate. The 5/16" screws flushed up perfectly to the bottom of the MOS plate - maximum thread engagement without any protrusion through the bottom. I'm happy with that.

I also ordered M3-0.5 x 10mm alloy steel screws (part # 94414A714) for my Sig P365XL and Holosun 507K. I wasn't sure since I was going by the Romeo Zero instructions which don't list screw length, but 10mm matched the length of the screws that came with the Holosun perfectly. I test fit and (re)mounted the 507K with the new screws.

I'm (based on Caballoflaco's excellent post above) revising my mounting procedure to include pre-fitting the screws without threadlocker to ensure they fit correctly. Therefore, my new steps are:

1. Make sure pistol is empty
2. Field strip
3. Prepare all surfaces (slide, plates, screws, threads) by de-greasing.
4. Test-fit screws in threads to ensure proper fit.
5. Apply threadlocker to screws (preferably Loctite 248)
6. Thread the screws until resistance is felt and then alternate slight increases in torque for each screw using a torque wrench to the lowest torque specification of any of the interacting components.
7. Place indicator marks on the screws/plate or screws/optic with a toothpick to make it easier to identify a loose screw.

After a near disaster yesterday and a couple weeks ago with a paint-pen, I will no longer apply the paint directly from the pen. I'll use a toothpick now just like I do with Torque-Seal. I apply the paint to one of the alcohol prep-pad wrappers that I've used and then use the toothpick. I'd be tempted to just get a couple small jars of Testers paint, but having to stir them may be more of a pain compared to shaking the paint pen.

I have a 365XL on the way and will move one of my Holosun 407K’s over to it.
How have the screws you ordered held up?

SoCalDep
04-17-2021, 09:57 PM
I have a 365XL on the way and will move one of my Holosun 407K’s over to it.
How have the screws you ordered held up?

I haven't shot the P365XL very much. In fact, a couple weeks ago I shot it for the first time since mounting the optic. I probably have around 200 rounds through it with no issues. Sorry I can't give you more difinitive information but I'm confident in them.

Steve m
04-19-2021, 09:59 AM
Sorry if this has been gone over before, but for the dumb guy in the room, I want to order replacement screws from McMaster.
What sizes do I need?
Glock 19 Gen 5 with CH plate, Holosun 507C
-Plate to gun screw size/part#?
-Holosun to plate size/part#?
Glock 17 gen5 with Leupold DPP pro MOS plate
-MOS plate to gun size/part#?
-Leupold DDP to plate size/part#?

Thanks to all, still learning ref MRDS and trying to build up my spare parts bin.

Steve

SoCalDep
04-20-2021, 01:40 AM
Sorry if this has been gone over before, but for the dumb guy in the room, I want to order replacement screws from McMaster.
What sizes do I need?
Glock 19 Gen 5 with CH plate, Holosun 507C
-Plate to gun screw size/part#?
-Holosun to plate size/part#?
Glock 17 gen5 with Leupold DPP pro MOS plate
-MOS plate to gun size/part#?
-Leupold DDP to plate size/part#?

Thanks to all, still learning ref MRDS and trying to build up my spare parts bin.

Steve

For the G19 with the C&H plate, you’ll be using non-standard screws - 4-40 if I remember correctly for optic -plate, and I may be wrong. I haven’t gone down that rabbit hole yet, but based on feedback I’ve received from several other departments coupled with my own experience I think I might look at some stronger fasteners. 10 in/lbs is on the low end for a lot of torque wrenches (where they are not as accurate) but I have had some failures of the screws as have others. That’s not cool at such a low torque. I’m not sure what the plate-slide screws are other than they are metric M3 - I’d have to go back to my paperwork to give more details.

Your G17 should be using the supplied screws from Leupold if I am correct (I don’t own a DPP any more, so grain of salt and all). I haven’t found a fastener that is comparable to the dimensions supplied by Leupold, and with a very small sample size (most of the DPPs we’ve used until recently have been direct milled, which is way different than the factory options) I wouldn’t go any more than 15 in/lbs (Glock MOS spec is 13.3) on those screws. I have the MOS plate screw specs, but not with me and I don’t want to trust my memory. I’ll post that when I confirm it.

Similar to what I said in another post... there’s still a lot of learning to happen with this stuff. Sorry I don’t have good answers for you, but, as you mentioned in your post, we’re all kinda the dumb (newbies) in the room.

Steve m
04-20-2021, 08:16 AM
SoCalDep,

Thanks for there response. I have x2 complete set of screws from CHPWS on order now, along with a cpl extra screws for the Delta point pro,
those along with the Duracell 1632s and 2032s I ordered should be good for a "in case something breaks scenario".
This thread is extremely helpful in allowing people to read what actually works and doesn't work for others.

W/R
Steve

1911Nut
04-20-2021, 01:07 PM
Any chance we could make this thread a "sticky"?

spelingmastir
07-17-2021, 12:15 PM
FYI the McMaster 6-32 5/16 alloy steel screws don’t fit flush with a Holosun 507c. The head has the proper angle but sits proud of the countersink as it doesn’t have as sharp a head edge as the stock screw. It’s been tough finding a torx head alloy steel screw that fits.

D-der
07-17-2021, 05:07 PM
FYI the McMaster 6-32 5/16 alloy steel screws don’t fit flush with a Holosun 507c. The head has the proper angle but sits proud of the countersink as it doesn’t have as sharp a head edge as the stock screw. It’s been tough finding a torx head alloy steel screw that fits.

Yup,
I can confirm this, I've got a box, actually 2
I questioned McMaster when the head didn't fit,
They promptly sent another box....NFG.
I've been in touch with Primary machine who milled
two of my guns for 507Cs, Bruce was no help, told me
to contact Holosun to see what the sent with the sight???
That's what they used ??? (thanks)
Holosun was consumer friendly, confirmed 6-32 and
stated they send 2 lengths.
I still haven't had any luck matching them up, in the next month or so it's time to change the battery in a bottom
battery 507C, any updated info would be much appreciated!

banzaijohn
07-17-2021, 06:06 PM
Yup,
I can confirm this, I've got a box, actually 2
I questioned McMaster when the head didn't fit,
They promptly sent another box....NFG.
I've been in touch with Primary machine who milled
two of my guns for 507Cs, Bruce was no help, told me
to contact Holosun to see what the sent with the sight???
That's what they used ??? (thanks)
Holosun was consumer friendly, confirmed 6-32 and
stated they send 2 lengths.
I still haven't had any luck matching them up, in the next month or so it's time to change the battery in a bottom
battery 507C, any updated info would be much appreciated!

i spoke w Holosun and they said the screw is 6-32 x 7.5mm, slightly shorter than 5/16 (this is the shorter proprietary screw with a narrow head). They’re in the process of making them available for order on their website. I was able to buy a bag of 50 for $17.50. They had to go with the narrower head to make room for the electronics in the newer versions of their sights. Holosun has excellent customer service, offering to send extra screws free, just need a pic of the sight’s serial no., but I needed a larger qty. I spoke with kelviny@holosun.com through their customer service contact.

dfeder530
07-17-2021, 07:15 PM
Sorry if this has been gone over before, but for the dumb guy in the room, I want to order replacement screws from McMaster.
What sizes do I need?
Glock 19 Gen 5 with CH plate, Holosun 507C
-Plate to gun screw size/part#?
-Holosun to plate size/part#?
Glock 17 gen5 with Leupold DPP pro MOS plate
-MOS plate to gun size/part#?
-Leupold DDP to plate size/part#?

Thanks to all, still learning ref MRDS and trying to build up my spare parts bin.

Steve

I can say with certainty that the screws that attach a plate to the MOS slide is a M3x0.5mm 6mm in length. The ones I use have a tensile breaking strength of 140,000 PSI. These screws I believe are also the same that bigtexoutdoors.com sells as MOS screw replacements. This is the exact screw number you can buy on McMaster-Carr: 94414A712

D-der
07-17-2021, 07:26 PM
i spoke w Holosun and they said the screw is 6-32 x 7.5mm, slightly shorter than 5/16 (this is the shorter proprietary screw with a narrow head). They’re in the process of making them available for order on their website. I was able to buy a bag of 50 for $17.50. They had to go with the narrower head to make room for the electronics in the newer versions of their sights. Holosun has excellent customer service, offering to send extra screws free, just need a pic of the sight’s serial no., but I needed a larger qty. I spoke with kelviny@holosun.com through their customer service contact.

Thanks very much, appreciate the information.
I've also found Holosun's customer service to be very good,
perhaps the gentleman I exchanged email with wasn't aware,
I'll try this contact first of the week.

SoCalDep
07-17-2021, 11:29 PM
FYI the McMaster 6-32 5/16 alloy steel screws don’t fit flush with a Holosun 507c. The head has the proper angle but sits proud of the countersink as it doesn’t have as sharp a head edge as the stock screw. It’s been tough finding a torx head alloy steel screw that fits.

I’m assuming you’re talking about a Glock MOS right? I’ve used those McMaster screws with no problems on a 407A with a G17MOS and with a 407COx2 on an M&P CORE (using 6-32x1/2” screws).

I do know that the McMaster stainless alloy screws have a head that barely fits the RMR and is too big for the Holosun. In my experience the regular alloy steel screws work fine. I’ll have to check this out.

spelingmastir
07-18-2021, 07:02 AM
I’m assuming you’re talking about a Glock MOS right? I’ve used those McMaster screws with no problems on a 407A with a G17MOS and with a 407COx2 on an M&P CORE (using 6-32x1/2” screws).

I do know that the McMaster stainless alloy screws have a head that barely fits the RMR and is too big for the Holosun. In my experience the regular alloy steel screws work fine. I’ll have to check this out.

This is for an AIM Surplus slide with RMR cut. Thanks for all of the info you have provided.

Archer1440
07-19-2021, 09:57 AM
I’m assuming you’re talking about a Glock MOS right? I’ve used those McMaster screws with no problems on a 407A with a G17MOS and with a 407COx2 on an M&P CORE (using 6-32x1/2” screws).

I do know that the McMaster stainless alloy screws have a head that barely fits the RMR and is too big for the Holosun. In my experience the regular alloy steel screws work fine. I’ll have to check this out.

As you know, (but for the edification of others)

Alloy steel screws are generally far superior in strength to stainless steel, which can have as little as half the strength (and tends to strip out a lot more easily as well).

SoCalDep
07-19-2021, 07:24 PM
As you know, (but for the edification of others)

Alloy steel screws are generally far superior in strength to stainless steel, which can have as little as half the strength (and tends to strip out a lot more easily as well).

Very true… McMaster does have “alloy” stainless screws that have very high tensile strength and great corrosion resistance, but they are WAY more expensive and the head is larger. They will fit RMRs but not Holosuns.

For most users the alloy steel are best but for some using the RMR the alloy stainless may be worth it.

Archer1440
07-19-2021, 09:29 PM
Very true… McMaster does have “alloy” stainless screws that have very high tensile strength and great corrosion resistance, but they are WAY more expensive and the head is larger. They will fit RMRs but not Holosuns.

For most users the alloy steel are best but for some using the RMR the alloy stainless may be worth it.

Correct, the specific one of the few alloys in stainless that is “strong enough” and available in suitable configurations is 17-4 PH (precipitation hardening) stainless, which is among the strongest of the stainless steels, and can be within 10% of the tensile strength of an otherwise equivalent carbon alloy fastener- IF it is properly heat treated.

The reason it’s more expensive is the material costs more, it needs slower cutting speeds in fabrication, and precise heat-treat is required.

That particular one is among the SS alloys that “stains less”- it will, in fact, oxidize in various conditions- but almost certainly not on one’s pistol.

DpdG
07-19-2021, 09:44 PM
Any chance someone has the part number/link for the M3x6mm MOS plate mounting screws in the correct alloy stainless? CH used the same screws to mount a custom plate for my 320 and I'd like some spares but will not do business with C&H. Likely don't need a box of 50-100, but maybe 10 or so would be fine.

Archer1440
07-19-2021, 09:55 PM
Any chance someone has the part number/link for the M3x6mm MOS plate mounting screws in the correct alloy stainless? CH used the same screws to mount a custom plate for my 320 and I'd like some spares but will not do business with C&H. Likely don't need a box of 50-100, but maybe 10 or so would be fine.

M3 x 6mm in coarse, or fine pitch? If 0.5mm (coarse) pitch you want these. The black oxide version: https://www.mcmaster.com/94414A712/

10 bucks for 100 of them. 12.9 spec for strength, which is the standard for this application. You won’t easily find these in stainless.

You can, however, get these zinc-plated which solves corrosion. https://www.mcmaster.com/90236A119/

$5.97 for a pack of 50.

DpdG
07-20-2021, 01:02 AM
I think they are 0.5 thread. Would A286 stainless be inappropriate? I found these on McMaster, although they are showing about $6/screw: https://www.mcmaster.com/94331A102/

spelingmastir
07-20-2021, 02:53 AM
I think they are 0.5 thread. Would A286 stainless be inappropriate? I found these on McMaster, although they are showing about $6/screw: https://www.mcmaster.com/94331A102/

Oh I bought two of those as well for my C&H 509t MOS plate and they don’t fit. The head diameter is too big.

DpdG
07-20-2021, 04:13 AM
Oh I bought two of those as well for my C&H 509t MOS plate and they don’t fit. The head diameter is too big.

Good to know as mine is a 320/R1P to 509T plate and concerning, given the standard head diameter for this style/size screw appears to be in the area of 6.4mm (the stainless) to 6.7mm (black oxide). Oh C&H how I rue the day...

Archer1440
07-20-2021, 01:16 PM
I think they are 0.5 thread. Would A286 stainless be inappropriate? I found these on McMaster, although they are showing about $6/screw: https://www.mcmaster.com/94331A102/

17-4PH is a lot stronger than A286- factor of about 2X. A286 is better than 17-4 at temperatures that would vaporize the frame on any polymer pistol, but isn’t the best choice for optics mounting.

Now, whether that difference is “enough to make a difference”, I don’t know.

Clark Jackson
07-20-2021, 06:16 PM
FWIW: Glock 17 Gen4 MOS. Forward Controls Design OPF-G, RMR plate. Trijicon RMR Type 2 RM06.

McMaster-Carr (https://www.mcmaster.com/)

94414A146 (https://www.mcmaster.com/94414A146/) - Black-Oxide Alloy Steel Torx Flat Head Screws, 6-32 Thread Size, 3/8" Long, Packs of 50 ($9.12/pack) *Sight-to-plate screw for FCD OPF-G, RMR plate.

91294A126 (https://www.mcmaster.com/91294A126/) - Black-Oxide Alloy Steel Hex Drive Flat Head Screw, 90 Degree Countersink Angle, M3 x 0.50 mm Thread, 6 mm Long, Packs of 100 (4.52/pack) *OPF-G, RMR plate-to-slide screw (same screw used for Glock MOS plates).

75145A68 (https://www.mcmaster.com/75145A68/) - Reusable Threadlocker, Vibra-Tite Vc-3, 0.17 oz. Tube

Other useful information concerning FCD’s OPF-G, RMR plate (https://www.forwardcontrolsdesign.com/OPF-G-RMR_p_224.html):
Plate to slide torque value: 13in/lb
Sight to plate torque value: 13in/lb

Clusterfrack
08-29-2021, 10:44 AM
Does anyone know the proper MRO screw size for a CZ Shadow2 with CZC slide cut and adaptor plate?

(WTF? Why would CZC not include shorter screws with the plate?)

GJM
08-29-2021, 11:20 AM
Does anyone know the proper MRO screw size for a CZ Shadow2 with CZC slide cut and adaptor plate?

(WTF? Why would CZC not include shorter screws with the plate?)

YVK has that set up and will know.

YVK
08-29-2021, 11:42 AM
Does anyone know the proper MRO screw size for a CZ Shadow2 with CZC slide cut and adaptor plate?

(WTF? Why would CZC not include shorter screws with the plate?)

Dont remember off the top exactly but I am almost nearly certain that those are standard RMR /SRO screws. And yes, CZC should include screws.

Clusterfrack
08-29-2021, 12:20 PM
Dont remember off the top exactly but I am almost nearly certain that those are standard RMR /SRO screws. And yes, CZC should include screws.

Unfortunately not standard SRO screws (which came with the optic). I guess I'll cut them short with a dremel...

(Getting the CZC plate for Sig Romeo off was a PIA. It took Kroil, and a torch to loosen the screws, but I guess that's a good thing so it didn't come loose during firing.)

GJM
08-29-2021, 01:04 PM
Unfortunately not standard SRO screws (which came with the optic). I guess I'll cut them short with a dremel...

(Getting the CZC plate for Sig Romeo off was a PIA. It took Kroil, and a torch to loosen the screws, but I guess that's a good thing so it didn't come loose during firing.)

My recollection is they need to be shortened. What I don’t recall is the exact dimension and what McMaster is available in the correct length.

Clusterfrack
08-29-2021, 01:24 PM
My recollection is they need to be shortened. What I don’t recall is the exact dimension and what McMaster is available in the correct length.

I just shortened them. I hate fiddly aftermarket parts.

Nephrology
08-29-2021, 06:39 PM
So Maple Leaf specifies 6-32 x 0.4" for their RMR screws.... does mcmaster carr make anything in that size? or should I just get 1/2" and file down the extra 0.1"?

23JAZ
09-09-2021, 09:28 AM
The 507K comes with M4 X .7 Torx with a .250” (6.35mm) diameter head but it’s 12mm long. Anything with a bigger head diameter binds on the sides of the sight and anything longer than 10mm binds the extractor spring. Does anyone know where I can find an M4 X .7 x 10mm with a 6.35 mm head diameter in black oxide with a torx head or whatever the inch equivalent is? I have checked all the usual suspects and cannot find it. Grinding the Holosun screws works but I’d rather not and I like replacing screws with the batteries so I need extra.

johnson
09-24-2021, 09:28 PM
I just got an HK VP9 and Holosun 507K X2 and after reading this thread I ordered Loctite 248 and McMaster-Carr 94414A146 and 94414A148 which I got today. Shout out to them for super fast shipping. I ordered on 09/23 at 6am and they were delivered the next day.

GJM and others mentioned that these are Torx screws but I just wanted to say that they're actually Torx-Plus so I also ordered a Torx-Plus IP15 from them (turns out to be Wiha brand) and picked up a couple of Felo brand T15 and IP15 bits from KC Tool as extras.

The thread size for the HK optic plates are supposed to be 6-32 but the factory screw as well as the new McMaster-Carr 6-32 screws are still a little sloppy.

Let me know if these resolutions are too large.

The factory screw stripped while I was trying to torque to 15 in-lb. I didn't even bother trying the other one and ordered replacements yesterday.

https://i.imgur.com/2KlgeLO.jpeg

Here's the new McMaster-Carr 6-32 after torquing down one time without Loctite 248. I just put in a new set of screws with Loctite 248 and am waiting >24 hours to shoot with it.

https://i.imgur.com/COUSkza.jpg


https://i.imgur.com/jZ6TcFP.jpeg

https://i.imgur.com/yvUMtm3.jpeg

https://i.imgur.com/axPLedW.jpeg

https://i.imgur.com/ad5V19m.jpeg

https://i.imgur.com/pj2H30z.jpeg

The Felo bits looks like they've been grinded down after production while the Wiha looks like it was formed that way. Any tool people want to comment?

https://i.imgur.com/7nlDgRz.jpeg

https://i.imgur.com/TIAqTQh.jpeg

Controlledpairs2
12-06-2021, 07:52 AM
Could I ask for some assistance? I am looking for replacement T Nuts like the ones used in CHPWS and LTT RDO plates. I haven't had a response from CHPWS, who's website says they produce them in house now due to QC issues from their last source. Does anyone know a reliable source for replacement T Nuts? I would like to replace the T Nuts whenever possible when remounting optics. Thanks.

Clusterfrack
04-18-2022, 03:55 PM
Is it correct that these will work for mounting a SRO? (assuming shortened to fit)
Camcar - #6–32 UNC Torx Plus 82° Flat Socket Cap Screw – Alloy Steel, Black Oxide, Fully Threaded, 1/2"
https://www.mscdirect.com/product/details/60502069

GJM, what are you using?

GJM
04-18-2022, 04:18 PM
Is it correct that these will work for mounting a SRO? (assuming shortened to fit)
Camcar - #6–32 UNC Torx Plus 82° Flat Socket Cap Screw – Alloy Steel, Black Oxide, Fully Threaded, 1/2"
https://www.mscdirect.com/product/details/60502069

GJM, what are you using?

Just to clarify, what optic, what pistol, and what plate are we talking about?

Clusterfrack
04-18-2022, 05:00 PM
Just to clarify, what optic, what pistol, and what plate are we talking about?

SRO. This one is on a CZC plate. But I have another one coming for direct mount to a RMR/SRO footprint.

GJM
04-18-2022, 05:18 PM
SRO. This one is on a CZC plate. But I have another one coming for direct mount to a RMR/SRO footprint.

Not sure, although I bet Stuart at CZ Custom will know what their plate requires.

Without info, I would see what screw matches that thread and then stick the screw through the optic and see how much engagement you will have. If too long you can pinch things that compromise function on some installations.

Clusterfrack
04-18-2022, 05:32 PM
Not sure, although I bet Stuart at CZ Custom will know what their plate requires.

Without info, I would see what screw matches that thread and then stick the screw through the optic and see how much engagement you will have. If too long you can pinch things that compromise function on some installations.

It's not the length I'm trying to match. The CZC screws are a custom length, so I'm going to have to trim no matter what.

I want to buy a bunch of screws that have a head with the best fit to the SRO.

DaBigBR
04-18-2022, 05:32 PM
Could I ask for some assistance? I am looking for replacement T Nuts like the ones used in CHPWS and LTT RDO plates. I haven't had a response from CHPWS, who's website says they produce them in house now due to QC issues from their last source. Does anyone know a reliable source for replacement T Nuts? I would like to replace the T Nuts whenever possible when remounting optics. Thanks.

If you aren't getting answer, email:

buck@chpws.com

JCN
04-18-2022, 06:49 PM
It's not the length I'm trying to match. The CZC screws are a custom length, so I'm going to have to trim no matter what.

I want to buy a bunch of screws that have a head with the best fit to the SRO.

Any flat screw head of appropriate diameter thread will work just fine.

I bought a whole tray in different lengths, metric and standard because going back and forth from Holosun and Trijicon requires different heads.

Also, some SRO mounts with posts require M3 or M4 flat heads.

Clusterfrack
04-18-2022, 07:12 PM
Any flat screw head of appropriate diameter thread will work just fine.

I bought a whole tray in different lengths, metric and standard because going back and forth from Holosun and Trijicon requires different heads.

Also, some SRO mounts with posts require M3 or M4 flat heads.

Do you have a link to that tray?

EzGoingKev
09-25-2022, 07:08 PM
I need some 6-32 by 9/16" long. I found these two:

McMaster-Carr (https://www.mcmaster.com/91253A166/)

Fastenere (https://www.fastenere.com/6-32-x-916-flat-head-socket-cap-screws-black-oxide-alloy-steel-qty-50?device=c&network=g&keyword=&creative=553513403027&placement=)

They both have allen heads. I prefer T15 torx but could not find any. Does anyone have a source for what I am looking for?

maximus83
01-09-2023, 03:51 PM
G19.5 MOS
Holosun 507c
CHPWS GL-RSH V4 (https://chpws.com/product/glock-mos-v4-mil-leo-to-trijicon-rmr-sro-holosun-407c-507c-508c-508t/) (RMR/SRO/407c/507c/508t)
* Replacement screw kit for GL-RSH (https://chpws.com/product/replacement-screw-kit-gl-rsh/)

CHPWS is out of the replacement screw kits I need, and didn't respond to service requests (voice, email). Ordering screws from McMaster.

Plate-to-slide:
* As earlier in thread: Zinc-plated alloy steel M3 x 0.5 mm Thread Size, 6 mm long (https://www.mcmaster.com/90236A119/)

Holosun-to-plate :
* Black oxide alloy steel 4-40 x 1/4 in long
(https://www.mcmaster.com/91253A106/)
Should these sizes work for the screws?

Ideas on where to get replacement T-nuts, since CHPWS is out of kits and not responding?

SoCalDep
01-10-2023, 12:16 AM
G19.5 MOS
Holosun 507c
CHPWS GL-RSH V4 (https://chpws.com/product/glock-mos-v4-mil-leo-to-trijicon-rmr-sro-holosun-407c-507c-508c-508t/) (RMR/SRO/407c/507c/508t)
* Replacement screw kit for GL-RSH (https://chpws.com/product/replacement-screw-kit-gl-rsh/)

CHPWS is out of the replacement screw kits I need, and didn't respond to service requests (voice, email). Ordering screws from McMaster.

Plate-to-slide:
* As earlier in thread: Zinc-plated alloy steel M3 x 0.5 mm Thread Size, 6 mm long (https://www.mcmaster.com/90236A119/)

Holosun-to-plate :
* Black oxide alloy steel 4-40 x 1/4 in long
(https://www.mcmaster.com/91253A106/)
Should these sizes work for the screws?

Ideas on where to get replacement T-nuts, since CHPWS is out of kits and not responding?

I looked at the plate-to-slide screws you linked and they show “not rated” for tensile strength and sourced from numerous countries. I prefer the alloy steel screws made in the USA and rated at 140,000 psi tensile strength. They are item number 94414A712 from McMaster.

As for the CHPWS compatible screws, I have the 4-40 x 1/4” with torx drive for Holosun - CHPWS plate, which is item number 94414A106. The screws for RMR - CHPWS plate (4-40 x 5/16”) are item 94414A322.

I also ordered some 4-40 x 3/8” screws (item 94414A108) and I can’t remember exactly why, but Langdon Tactical for their 92 series mill/plate, Agency Arms, and CHPWS use 4-40 screws. It probably had to do with one of those.

I won’t trust what is “listed”, and I’ll test fit the optic to the plate to see how deep the screw sits in the T-nut and/or plate and may go with either/any of the recommended lengths based on how it fits.

To be honest... With a Glock MOS unless you bent the factory plate by using the wrong screws or massive abuse in shipment or handling, if mounted right I prefer it to CHPWS. I prefer the Forward Controls Design (If available for your optic) to either.

I have no idea where to get T-nuts besides CHPWS, but I have a few sets so if you PM me your address I’ll send you a set.

maximus83
01-10-2023, 12:46 AM
SoCalDep thanks, great info not easily obtainable anywhere else.

Based on your comments:
* I have an FCD plate on my G45 for my SRO, love it. Could I use an FCD for my Holosun 507c? Their website (https://www.forwardcontrolsdesign.com/OPF-G-RMR_p_224.html)suggests the 507c will work with their plate, *if* you use the shorter screws.
* Interesting you prefer the OEM MOS plates to CHPWS. I think if I'd know that I wouldn't have bothered with the CHPWS.

SoCalDep
01-10-2023, 01:19 AM
SoCalDep thanks, great info not easily obtainable anywhere else.

Based on your comments:
* I have an FCD plate on my G45 for my SRO, love it. Could I use an FCD for my Holosun 507c? Their website (https://www.forwardcontrolsdesign.com/OPF-G-RMR_p_224.html)suggests the 507c will work with their plate, *if* you use the shorter screws.
* Interesting you prefer the OEM MOS plates to CHPWS. I think if I'd know that I wouldn't have bothered with the CHPWS.

FCD says maybe (you can use a Holosun) but last I saw they won’t specifically list it as compatible. I’ve installed a couple Holosuns and they worked - but it’s a “YMMV” thing. You do need to use shorter screws, and that’s another issue because the Holosun 507C needs a thinner head compared to the RMR as well as being shorter (5/16” vs 3/8”). For the Holosun - MOS (which would be the same as a FCD plate) I use the zinc-coated steel screws from McMaster or the shorter screws included with the Holosun (test fit with the optic in the plate before installation to make sure they don’t protrude, which will bend the plate). The McMaster screw item number is 90920A274, which is for the 6-32 x 5/16”.

As for the MOS vs CHPWS, I think the company is being super responsive to the industry and I’m happy for that. They have been very responsive to fix some issues my department had, and they are, more than anyone else, trying to make as many optics fit on as many pistols as possible. So... I like CHPWS. They have their issues because they were a small company that got big maybe faster than they were prepared for.

The reason I’m a fan (right now) of the MOS over the CHPWS is because I feel that when mounted properly, a 6-32 screw is stronger against torque and shear forces than a 4-40, and though C&H uses T-nuts that support the screws, the 4-40 torqued down against the optic can shear (I’ve sheared a few until I started using alloy steel screws) and I’ve seen as many issues with screws shearing off during firing with C&H as I’ve seen with MOS. Done right with the right length and enough but not too much threadlocker (NOT VC-3!!!!!!!) they do work very well.

I just think based on what I think I’ve learned that as long as there’s enough thread engagement, which isn’t all that much, it’s about not coming loose. An MOS has enough engagement and when mounted correctly won’t come loose. I actually spent my own money to have a few sets of C&H plates for our guys with M&Ps that show up to mount optics and didn’t realize they needed the plates from the factory box... but ultimately my favorite plate for Glocks is the FCD and it’s the same screw size and thread engagement as the MOS...

Archer1440
01-10-2023, 02:01 AM
Just a quick note to mention that my recent experience buying a plate from FCD might very well be the absolute best service I have ever experienced for anything- much less stuff in the firearms space. If every company handled orders the way they did, there would never be a need for customer service representatives. Just amazing.

Also I really appreciate how they labeled the included screws with the exact specifications. The quality of the plate was just outstanding too.

WobblyPossum
01-12-2023, 10:08 PM
What would be the McMaster Carr part number for screws to replace the OEM Sig Sauer screws to mount a Romeo 1 Pro to a factory optics-ready P320?

SoCalDep
01-13-2023, 12:03 AM
What would be the McMaster Carr part number for screws to replace the OEM Sig Sauer screws to mount a Romeo 1 Pro to a factory optics-ready P320?

I wish I could give you a good answer but I haven’t found any. I ended up ordering a set of screws from Sig just in case. The only P320ish pistol I have is an M17 and it’s a training/loaner gun with a DPP on it. I ordered the screws in case I have a student that needs a loose optic re-mounted. Thankfully Sig does a good job mounting their optics.

WobblyPossum
01-13-2023, 09:02 AM
I wish I could give you a good answer but I haven’t found any. I ended up ordering a set of screws from Sig just in case. The only P320ish pistol I have is an M17 and it’s a training/loaner gun with a DPP on it. I ordered the screws in case I have a student that needs a loose optic re-mounted. Thankfully Sig does a good job mounting their optics.

Thanks for letting me know. A couple of guys at my office just left the agency and I want to pull the optics off the duty guns they turned in before I send the guns back to the national armory. I would prefer to have new screws to mount them later. I’ve read it’s less of a worry that the old screws would snap if reused because of their size compared to other brands’ mounting screws. Is that correct?

Clusterfrack
01-16-2023, 11:24 AM
I can confirm that the following screws fit the Holosun 509T X2 battery tray:
McMaster Carr 91294A002 (https://www.mcmaster.com/catalog/91294A002)
Black-Oxide Alloy SteelHex Drive Flat Head Screw, 90 Degree Countersink Angle, M2 x 0.40
Socket: 0.050” hex (https://www.mcmaster.com/catalog/7122A13)

@RJ, thoughts about adding battery tray screw info to your Quick Reference Cards (https://pistol-forum.com/showthread.php?51980-MRDS-Quick-Reference-Cards-(Revision-10-Release))?

As well, I can confirm that the Holosun EPS uses a larger screw for the battery tray, but do not have the dimensions. Anyone know what McMaster part fits the EPS?

js475
02-10-2023, 11:27 PM
I want to get some extra screws from McMaster to mount a Holosun 507C X2 to a Glock MOS plate. After reading through this thread it seems there have been a few different recommendations with some having issues with the angle of the screw head on the McMaster screws. What's the latest consensus on the correct screw to use for the Holosun?

CalAlumnus
02-11-2023, 04:13 AM
Has anyone found quality screws compatible with the Holosun SCS MOS?

SoCalDep
02-12-2023, 01:12 AM
Has anyone found quality screws compatible with the Holosun SCS MOS?

If I remember correctly the SCS MOS uses the same M3 screws as the MOS plate (6mm), so the McMaster-Carr screws that are recommended for the MOS plates should work. I don’t know about most of the newer versions for other pistols but I know the S&W M&P version uses what appears to be proprietary screws.

SoCalDep
02-12-2023, 01:23 AM
I want to get some extra screws from McMaster to mount a Holosun 507C X2 to a Glock MOS plate. After reading through this thread it seems there have been a few different recommendations with some having issues with the angle of the screw head on the McMaster screws. What's the latest consensus on the correct screw to use for the Holosun?

I would recommend the McMaster-Carr zinc-plated steel screws that are 6-32x5/16” or the Holosun factory (short) screws. I have several of both but I do most of my mounting with the McMaster screws. I would prefer the stainless or alloy steel screws, but the head diameter is too wide for the Holosun countersinks/optic body. That’s why I ended up with the zinc-plated screws. I feel that as long as the screw stays tight (through proper mounting procedures), the screws strength is less important. If it comes loose, a stronger screw will give more wiggle-room before it dies completely.

js475
02-12-2023, 12:21 PM
I would recommend the McMaster-Carr zinc-plated steel screws that are 6-32x5/16” or the Holosun factory (short) screws. I have several of both but I do most of my mounting with the McMaster screws. I would prefer the stainless or alloy steel screws, but the head diameter is too wide for the Holosun countersinks/optic body. That’s why I ended up with the zinc-plated screws. I feel that as long as the screw stays tight (through proper mounting procedures), the screws strength is less important. If it comes loose, a stronger screw will give more wiggle-room before it dies completely.

Thanks! Is the head diameter issue with the alloy steel screws just cosmetic (i.e. they just stick out on top a little), or does the head being too wide prevent it from securing the optic properly? I think I'd prefer the stronger screws if the issue is mostly cosmetic.

SoCalDep
02-12-2023, 12:46 PM
It prevents the screw from fully seating in the countersink. It is less of an issue with the aluminum models (407/507) but frequently caused problems with the titanium 508Ts.

I now use the smaller diameter heads for all of them because between screw strength and a good mount you want a good mount every time.

NuJudge
02-24-2023, 09:43 PM
I bought a SIG P226 slide with an already mounted SIG Romeo1 Pro red dot on it from RTG. It came without the steel Shroud that SIG makes for it and the Romeo 1. I went and got the Shroud. The screws that came with the shroud don't fit the Romeo1 Pro, they fit the Romeo 1. Very odd. Questions and answers on the website I bought the shroud from say the screws for the Romeo 1 Pro are:

M4 x 0.7 thread pitch x 8.5 mm shaft length high-strength alloy screws (12.5 mm overall length (Torx head)

Can someone tell me which McMasterCarr part number is what I need as a replacement?

SoCalDep
02-24-2023, 10:37 PM
I bought a SIG P226 slide with an already mounted SIG Romeo1 Pro red dot on it from RTG. It came without the steel Shroud that SIG makes for it and the Romeo 1. I went and got the Shroud. The screws that came with the shroud don't fit the Romeo1 Pro, they fit the Romeo 1. Very odd. Questions and answers on the website I bought the shroud from say the screws for the Romeo 1 Pro are:

M4 x 0.7 thread pitch x 8.5 mm shaft length high-strength alloy screws (12.5 mm overall length (Torx head)

Can someone tell me which McMasterCarr part number is what I need as a replacement?

They (McMaster's suppliers) don't make one as far as I can tell. I bought an extra set (I don't even use those screws... just to have in case someone needs them) from Sig. Do the old screws for your R1P optic not work?

NuJudge
02-25-2023, 06:01 AM
They (McMaster's suppliers) don't make one as far as I can tell. I bought an extra set (I don't even use those screws... just to have in case someone needs them) from Sig. Do the old screws for your R1P optic not work?

The old screws wok, but I like having spairs.

SoCalDep
02-25-2023, 06:24 AM
The old screws wok, but I like having spairs.

I’m with you there… if you find a supplier other than Sig please let me know.

Elwin
11-13-2023, 08:44 PM
Resurrecting this thread because I'm at a loss for what I'm trying to do.

Impact Machine used M4 screws for the EPS Carry dots they installed for me. I measure the length as 9.4mm - no problem, I can file a 10mm length. My problem is the head diameter - I'm unable to find a Torx M4 screw with a head diameter of 6mm to 6.5mm (Holosun factory is ~6mm and the Impact screws are ~6.4mm). The closest McMaster-Carr I'm finding has an 8.4mm head. They're also zinc-plated, and while that's not a deal breaker I'd certainly prefer black oxide.

Is that a small enough difference to not matter because at worst it will just stand a bit proud while still working, or do I need something else? First time dot owner and I'm way out of depth with the screw part of it.

Whiskey_Bravo
11-14-2023, 09:04 PM
Resurrecting this thread because I'm at a loss for what I'm trying to do.

Impact Machine used M4 screws for the EPS Carry dots they installed for me. I measure the length as 9.4mm - no problem, I can file a 10mm length. My problem is the head diameter - I'm unable to find a Torx M4 screw with a head diameter of 6mm to 6.5mm (Holosun factory is ~6mm and the Impact screws are ~6.4mm). The closest McMaster-Carr I'm finding has an 8.4mm head. They're also zinc-plated, and while that's not a deal breaker I'd certainly prefer black oxide.

Is that a small enough difference to not matter because at worst it will just stand a bit proud while still working, or do I need something else? First time dot owner and I'm way out of depth with the screw part of it.

I am glad you posted this. I just received an 11-71 plate for my Glock MOS to mount an EPS to. Looking for specifications as well to order in bulk.

Elwin
11-22-2023, 08:24 PM
Resurrecting this thread because I'm at a loss for what I'm trying to do.

Impact Machine used M4 screws for the EPS Carry dots they installed for me. I measure the length as 9.4mm - no problem, I can file a 10mm length. My problem is the head diameter - I'm unable to find a Torx M4 screw with a head diameter of 6mm to 6.5mm (Holosun factory is ~6mm and the Impact screws are ~6.4mm). The closest McMaster-Carr I'm finding has an 8.4mm head. They're also zinc-plated, and while that's not a deal breaker I'd certainly prefer black oxide.

As mentioned in another thread and for the benefit of anyone reading this later, the 8.4mm head diameter screws 100% do not work.

rappy
01-02-2024, 09:05 PM
Hello,

New to the site, and have been reading this thread and others like it trying to make sense of all the different McMaster part #'s. And Honestly I have confused myself :confused: I have two Glock 43X's with EPS Carry. One is a direct milled JagerWerks and one is a MOS with CHPWS Adapter plate. I am trying to confirm I have my PN's correct. Any help confirming and or correcting my assumptions would be appreciated.

JagerWerks - Direct EPS Carry to 43X slide = 91253A147

MOS - EPS Carry to CHPWS Plate = 94414A723

MOS - CHPWS Plate to 43X Slide = 94414A712

Spare Battery screw = 91698A241

Thanks!