Czechmate Optic Mount to Frame Screw Size

[AaronUSMC]

Hey all,

 

I know the screws are M4x0.7, does anyone have the overall length? Looking to order some spares before I take it apart as I'm chasing down a loosening mount problem! I would just take the screw to the hardware store, but I have a match in a few days and don't want to lose my zero.

 

 

Edited October 19, 2023 by AaronUSMC
background info

[Toggleme]

I dont have an answer for you, but I will tell you these (or compatible) screws are cheap from grainger: 

 

 

Flat head screws spec their length from the top of the whole fastener, so you could remove your slide and take a rough measurement from the outside surface of your optic mounting plate to the inside of your frame. That would give you the longest it could possibly be. 

[AaronUSMC]

I'll try that tonight! 

[my00wrx1]

I would get torx screws to resolve this issue, don’t settle for hex. 

[JWBaldree]

On 10/18/2023 at 7:36 PM, AaronUSMC said:

Looking to order some spares before I take it apart as I'm chasing down a loosening mount problem!

 

 

I went through this exact same headache in year two of my Czechmate ownership. I tried all kinds of Loctite and primer combinations, and the problem just kept getting worse. VC3 thread locker was an improvement, but the end screws would back out eventually, within 300 rounds. I blind tapped the screw hole closest to the trigger so I could use a longer screw, but still had issues. Replaced all the screws, still had the problem.

 

I took the gun to a machinist I use and asked about having him cut, drill and tap for screw locks for the mounting screws, a-la Mauser 98. He looked at me like I had 3 heads and said we just needed to add some fixed locator pins to take up the recoil load, and allow the screws to perform just their function of supplying clamping load. The locator pins for the MRDS's or their mounting plates do the exact same thing. We set a date for me to bring the gun back so he could do it while I waited.

 

In the meantime, I was perusing CZ Customs webpage, and looked up their Czechmate mount. Low and behold, it has holes for locator pins already drilled in the mount, and the machining schematic is attached in the 'details' section. I printed off a copy, picked up some pins, and my guy drilled, reamed and installed the pins in 30 minutes. If I ever decide to ditch the full size CMore optic for something cooler I will be good to go with the CZC mount.

 

Knock on wood, my problem has been solved since. I still use VC3 for thread locker as I feel it is way moar gooder than Loctite for small screws and it gives me a warm fuzzy.

[AaronUSMC]

JWBaldree, I actually came across your post a while back and your solution is my next step, so thank you!
 

The length of these screws are 8mm for any future reference. 

[AaronUSMC]

For any future reference,

 

Found that with 8mm screws, they would leave a thread or two unused in the frame, so I bought a pack of 10mm instead and trimmed down the front two to 9.04mm so that it would just clear the slide, and the back screw to 9.10mm. I cleaned everything with tap/die and brake cleaner and used VC-3 and there is an improvement as I shot about 400 rounds last weekend and it stayed tight. Can't really say if its going to hold for good yet but it would usually loosen up well before 150 rounds before.

 

It this doesn't work, I'll be doing pins as @JWBaldree has done.

[old558]

On 11/9/2023 at 10:00 PM, AaronUSMC said:

For any future reference,

 

Found that with 8mm screws, they would leave a thread or two unused in the frame, so I bought a pack of 10mm instead and trimmed down the front two to 9.04mm so that it would just clear the slide, and the back screw to 9.10mm. I cleaned everything with tap/die and brake cleaner and used VC-3 and there is an improvement as I shot about 400 rounds last weekend and it stayed tight. Can't really say if its going to hold for good yet but it would usually loosen up well before 150 rounds before.

 

It this doesn't work, I'll be doing pins as @JWBaldree has done.

Were you able to solve your problem?