Screws To Attach 507k to Sig P365 XL?

[walker2713]

What screws do I need to put a Holosun 507k on my new Sig P365XL?

All help appreciated!!

George

[SoCalDep]

I use M3 x 0.5 x 10mm alloy steel screws from McMaster for the 507K and EPS Carry on Sig P365X series guns. Even though the screws sit a hair deeper with the EPS they still work great, they’re known high-strength and good quality.

Part number 94414A714.

[walker2713]

Many thanks…..we happen to have such a store in our small town.

[crosseyedshooter]

I use M3 x 0.5 x 10mm alloy steel screws from McMaster for the 507K and EPS Carry on Sig P365X series guns. Even though the screws sit a hair deeper with the EPS they still work great, they’re known high-strength and good quality.

Part number 94414A714.

Agreed that 10mm long is the correct length for 407k/507k direct-mounted to P365(X/XL/X-Macro) optic-ready slides. For EPS Carry, I went with 8mm (94414A713) screws which still work for 407k/507k.

[maximus83]

Agreed that 10mm long is the correct length for 407k/507k direct-mounted to P365(X/XL/X-Macro) optic-ready slides. For EPS Carry, I went with 8mm (94414A713) screws which still work for 407k/507k.

Interesting, I was about to order from McMaster based on previous comments in this thread, and the other thread about the EPS Carry.

What do you NOT like about the 10mm length screws for the EPS carry on P365-series? (Would be nice to not have to buy so many 100-piece boxes of one-off screw sizes that I'll probably only ever use a handful of ).

[crosseyedshooter]

What do you NOT like about the 10mm length screws for the EPS carry on P365-series? (Would be nice to not have to buy so many 100-piece boxes of one-off screw sizes that I'll probably only ever use a handful of ).

Below is a pic of the Holosun 12mm screw (left) and you can see the portion that’s damaged by going too deep into the unthreaded part of the slide. This screw actually bottomed out against the shoulder without securing an EPS Carry. On the right is an 8mm long screw. You can estimate where a 10mm long screw might be. I’d like a 9mm screw for EPS Carry, but oh well.

[Norville]

I used the ones in the 507k box…

There may be better options, but no issues so far.

[crosseyedshooter]

I used the ones in the 507k box…

There may be better options, but no issues so far.

If you mounted to the older slide (rear sight removes with plate) then it seems the threads go deeper, but I don’t have direct experience with them. If you have the newer slides that retain the rear sight, like I do, then here’s what my 407k screw (right) looked like after torquing to 15 in-lb:

[Norville]

If you mounted to the older slide (rear sight removes with plate) then it seems the threads go deeper, but I don’t have direct experience with them. If you have the newer slides that retain the rear sight, like I do, then here’s what my 407k screw (right) looked like after torquing to 15 in-lb:

Correct, I have the mostly the plate style slides.

[SoCalDep]

After crosseyedshooter’s post I checked on some stuff and learned things... so first, thanks to crosseyedshooter for your posts.

After reading the thread last week I pulled the M3-0.5 x 10mm screws out of my Sig P365 X Macro (plate is separate from rear sight) and noticed that the first thread was deformed. In my opinion this isn’t enough of an issue to say the 10mm length screws won’t work in the newer slide design with the EPS Carry, as mine and several others have worked fine. That said, I totally agree with crosseyedshooter that 12mm is a no-go, and 10mm is on the ragged edge of acceptable... I’m less than happy with that.

I ordered some 8mm screws from McMaster since I needed a resupply of some others as well, and I’m planning to compare thread engagement with an EPS Carry the next time someone brings in a Sig with the new design slide (rear sight independent of the optic plate), but I think 8mm should be plenty based on the number of rotations needed to seat the 10mm screws.