I've been mounting 508Ts at 20 in/lbs with Chip Whiz and factory plates on dept issued guns with McMaster Carr screws. So far so good. I had used the screws Chip Whiz sent with their plates torqued to 15 in/lbs on a 508t M&P and the screws sheared off inside the slide in about 700 rounds. The McMaster Carr screws are a bit longer than Chip Whiz or S&Ws.
For he is the minister of God to thee for good. But if thou do that which is evil, be afraid; for he beareth not the sword in vain: for he is the minister of God, a revenger to execute wrath upon him that doeth evil. Romans 13:4 KJV
At 10 in/lbs there won’t be much resistance regardless of fastener, but the McMaster Alloy Steel screw heads are too wide to work reliably with the open emitter Holosun optics. The 6-32x1/2” Stainless screws from McMaster have a smaller head diameter and work very well.
Just as I disregard a lot of the C&H mounting instructions (“staking” with paint and using VC-3 for a couple other examples) I don’t follow their instructions for the CORE plate. Direct optics (RMR, Holosun 407/507/508) get 15in/lbs. if using the plate for the 509T or ACRO (and that plate is a whole other issue) then I go 12in/lbs plate to slide and 15in/lbs optic to plate. I did a few at 15/20 in the past but didn’t want to break other people’s stuff by going too far off manufacturer recommendations.
Of the two ACRO plates I have from them I’ve never got past test fitting them to the slide. The trial isn’t over yet but it’s not looking good for the defense. When I recently got our P-2 back from another instructor I ended up going with the Aimpoint plate because it fit way more securely.
Thank you guys for the responses. I attempted to reinstall the optic and plate on the pistol this evening and noticed there was a significant gap between the plate and optic. The gap was significant enough that I could see light coming through during the dry fitting. At first I thought my Chip wiz plate was warped but then I tried it with the plastic oem smith plate and there was still a gap so I tried it with a v4 chip wiz plate for a glock and the gap was there as well. It appears that the area where the 4 screws on the bottom of the 508t protrude just enough to cause the gap to be there.
I don’t have a ton of experience mounting optics on pistols, is a small gap when just dry fitting the optic to the plate an issue? Thanks.
Is this the correct part number for McMaster screws for the holosuns and chps plate 92703A255 ?
Yep. That’s what I use.Originally Posted by rif4trbo
make sure the roll pin in front of the firing pin safety block cover is flush. I believe it was @SoCalDep that was saying he routinely has to tap it flush to prevent gaps like you are describing. Access it from the top of the cut with optic, plate, and covers removed.
As I mentioned my local PD had issues with the core optics mounting system failing with 40 Cal.
Here is the video @GJM posted in the 10mm M&P thread in which the reviewer is hit in the head by his optic breaking off the CORE mount under recoil and hitting him in the head at about the 14:00 minute mark. The optic breaks off after somewhere around 100-ish rounds of SIG and PMC range ammo.
Think about this, seems like the weak link is the polymer mounting plates that S&W uses?
Likes pretty much everything in every caliber.
Dumb question--is the CORE system different from the Optics Ready M&P models?
As I mentioned my local PD issues the M&P 40 cal, Has been actively testing optics and has experienced several failures of the S&W CORE mounting system.
Here’s the latest.
Officer/instructor doing T&E of the new Steiner pistol optic had the optic break off under recoil snd strike the shooter in the head.
The good news is the Steiner optic survived impact with both the Officer’s head and the ground and is ready to be re-mounted on another gun.
As you can see the Steiner’s ACRO cross bolt interface held up and the plate remains attached to the optic but the screws holding the plate to slide sheared.
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