CZ 75B w/ Factory Threaded Barrel - Enough shoulder for Suppressor?

[lordfarquaad]

I just fitted my CZ75B-SA with a new threaded barrel from the CZ website. I've also just finished shooting it with an Osprey 45K. Noticed I had to re-tighten the suppressor a couple times.

I did a bit of reading and noticed a few people saying that the CZ75 barrel isn't large enough to provide a proper shoulder to tighten up against a suppressor. They were speaking, I think, of barrels that had been threaded by a smith and not at the factory.

At any rate, can anyone here who has a factory CZ75B threaded barrel and a suppressor speak to this? Does it provide enough shoulder?

Mainly asking because I had to re-tighten and started to get nervous, thinking that it was possible that the reason I had to re-tighten was due to lack of shoulder, and that I might damage something if I kept it up. But maybe that was just me being nervous, and I can continue to tighten it up however much is necessary.

Thanks for any help.

 

[Theohazard]

I don’t have a factory-threaded CZ75B to look at, but I can tell you that I’ve sold a lot of P-01 threaded barrel models to customers who used them as suppressor hosts and I’ve never had anyone have an issue with the threads being an improper spec.

Having a pistol silencer loosten during firing is completely normal. It happens to me all the time on my Glock 19 host with my Octane 9. It’s just more noticeable on an Osprey since the silencer is odd-shaped (which is a good thing; it means you’ll notice it quicker and be able to re-tighten it before you get an encap strike).

There are ways to improve the loosening issue. Some people say that metric left-hand threads won’t allow the silencer to loosen due to the rifling twist direction of many pistol barrels. Me, I think it has more to do with the thread specs on the barrel and the o-ring used in the piston; the difference between metric threads and standard threads is more than just right-hand vs. left-hand. In my experience, left hand threads can still allow the silencer to loosen.

The best solution I’ve found to minimize loosening is to put a tiny drop of high-temp thread locker on the barrel threads and let it dry without the silencer attached. That will help the silencer stay tight while still being fairly easy to remove since it was already dry before you screwed the silencer on. But whatever you do, never use a lock washer or anything else between the silencer and the shoulder.

 

[MachIVshooter]

A lot of pistol barrels have little or no shoulder, just bottom out the threads. Screw them on as tight as you can, check the alignment, tighten periodically if it loosens.

When I do adapters, I'll often create a shoulder, but it just depends on whether or not someone is OK with the barrel being somewhat permanently installed or at least not really removable in field stripping.

 

[lordfarquaad]

Thank you MachIVshooter. That's good info for me, because I was basically assuming that "bottoming out the threads" would be bad news for either the piston or the barrel. Good to hear from a gunsmith that it's not something to be concerned about.

I'll just ask one more question:

I spoke to Silencerco and they said that they've run into something like this (although not with the CZ75B but with, I think, a Sig 938), and for that reason created a version of the 1/2x28 piston that times on the muzzle itself instead of the shoulder. It is on their product page and has a different suffix to indicate what it does.

Like you, the guy I spoke with didn't seem to think I actually needed this for the CZ75B, but he said I could always use it if I was worried about that. Would you say that there would be any merit to me getting one of those? Or is that completely unnecessary?

Thanks again for chiming in.

 

[MachIVshooter]

I spoke to Silencerco and they said that they've run into something like this (although not with the CZ75B but with, I think, a Sig 938), and for that reason created a version of the 1/2x28 piston that times on the muzzle itself instead of the shoulder. It is on their product page and has a different suffix to indicate what it does.

Like you, the guy I spoke with didn't seem to think I actually needed this for the CZ75B, but he said I could always use it if I was worried about that. Would you say that there would be any merit to me getting one of those? Or is that completely unnecessary?

Unless you're having alignment issues with a standard piston, hang on to your money.