Burrs in the Moderator

[Ian70]

This is inside my brand new Wildcat Panther's internal thread that you can clearly see is burred. When I initially installed the moderator it screwed on smoothly and came to a firm stop, feeling like both the moderator and the end of the barrel hate correctly mate. When I later went out to zero the rifle I couldn't hit a barn door. When I checked the end of the moderator I could clearly see it was in fact clipping. When I returned home I inspected the moderator with my endoscope and I could clearly see highlighted burr was preventing the full threading of the moderator onto the barrel end - thus slight misalignment and causing the clipping.

It was a brand new CZ 457's barrel that just had its factory muzzle break removed that went onto this moderator. I don't know a lot about engineering, but I do believe these burrs are created in the machining/manufacturing process, and the only way I'm going to be able to install this moderator correctly is by running a tap through it and using a high pressure hose to blow out the debris. I am glad it did feel like it had mated though, because trying to force thread something like this just would have chewed the thread up..

Has anyone else come across this before? Is it common? I've contacted Wildcat and I'm waiting to hear back from them.

 

[Greenmist]

Don't they come apart for cleaning etc, also check the thread on the rifle, not all factory threading is concentric with the bore

 

[8x57]

If it's a problem with Wildcat I'm sure that they will remedy it promptly. My limited experience with the company has been nothing but very positive.

 

[Ian70]

Don't they come apart for cleaning etc, also check the thread on the rifle, not all factory threading is concentric with the bore

It ended up with the pitch being wrong. The barrel is 1/2 20 and the moderator was 1/2 28. The moderator was sold together with the rifle so it was an oversight by the supplier. The supplier has apologised and is swiftly rectifying the error. The fact the moderator rolled on what I know know to had only been half way with no resistance whatsoever and came to an abrupt stop made me believe the thread was damaged. I'm glad I only tweaked it on and didn't give to firm tightening, otherwise I could have shreaded the threads and even locked the moderator on.


Being relatively knew to the world of firearms, I never even knew there were so many thread types. As they say "everyday's a school day". I'm just glad it's being sorted. I'll just have to continue to use the muzzle brake for now.

 

[Stalker-of-the-deer]

Cz 455 is 1/2" UNF threads which is what 1/2x 20 is and is one if the most common threads you will find in a rifles, air rifles and such in the uk.


1/2 x 28 is 1/2" UNEF - which is a finer thread is mostly found on AR15 type rifles and is also very common but not as much as 1/2" UNF.

 

[Onelesscharlie]

Something must have been very wrong, the two threads are nowhere near similar and should have locked up within half a turn. If it were me I would be looking to get the muzzle thread checked for damage.

 

[Ian70]

Something must have been very wrong, the two threads are nowhere near similar and should have locked up within half a turn. If it were me I would be looking to get the muzzle thread checked for damage.

The thread has been checked and the muzzle break rolls on. I think the moderator is allow thread too.

 

[Greenmist]

It ended up with the pitch being wrong. The barrel is 1/2 20 and the moderator was 1/2 28. The moderator was sold together with the rifle so it was an oversight by the supplier. The supplier has apologised and is swiftly rectifying the error. The fact the moderator rolled on what I know know to had only been half way with no resistance whatsoever and came to an abrupt stop made me believe the thread was damaged. I'm glad I only tweaked it on and didn't give to firm tightening, otherwise I could have shreaded the threads and even locked the moderator on.


Being relatively knew to the world of firearms, I never even knew there were so many thread types. As they say "everyday's a school day". I'm just glad it's being sorted. I'll just have to continue to use the muzzle brake for now.

Glad you got it sorted and more importantly, realised something was wrong. Might have been a different story if it was only held on with friction and you shot through it