AR Sponsor
Posted: 3/27/2026 1:22:12 PM EDT
|
Swapping a muzzle device over to a Plan B from Blackout Defense and it has no relief behind the threads. They essentially run all the way out to shoulder of the device. I can’t remember the last time I’ve had one come through the shop like this. It’s going to force us to use an excessively thick shim (thanks to Accu-Washer). I’ve contacted Blackout Defense and supposedly the engineer is out till Monday so no contact or reason yet. Are any other manufacturers still doing this with no shoulder relief? Attached File Attached File |
You think you're winning this game? You don't even know the God-damned rules. But don't worry, I'm gonna teach 'em to ya..
|
A relief is really only needed for parts made on a manual lathe. The point of it is to provide an area the machinist can kickout the feedscrew before the tool crashes. CNC makes it irrelevant. The muzzle threads in your pic could definitely of been cut closer to the shoulder. The muzzle device should have an appropriately sized chamfer, on the start of the threads, to compensate for the threads ending up against the shoulder. Just chuck up the muzzle device and turn the start to suit. |
|
The thread relief should be on the muzzle device, not on the barrel. If you cut a relief on the barrel, customers complain about their crush washer not being centered up. I agree with the post above.....the threads should have been cut up closer to the shoulder on that particular barrel. You don't need that much shank to center the washer. Tony |
|
Originally Posted By alpha0815: Swapping a muzzle device over to a Plan B from Blackout Defense and it has no relief behind the threads. They essentially run all the way out to shoulder of the device. I can’t remember the last time I’ve had one come through the shop like this. It’s going to force us to use an excessively thick shim (thanks to Accu-Washer). I’ve contacted Blackout Defense and supposedly the engineer is out till Monday so no contact or reason yet. Are any other manufacturers still doing this with no shoulder relief? https://www.ar15.com/media/mediaFiles/311137/IMG_2417_jpeg-3736942.JPGhttps://www.ar15.com/media/mediaFiles/311137/IMG_2418_jpeg-3736941.JPG That's exactly how the drawing shows the muzzle threads are supposed to be. |
|
Originally Posted By lysanderxiii: That's exactly how the drawing shows the muzzle threads are supposed to be. What drawing, the barrel? No beef with the barrel. Sure Noveske stopped the threads a bit shorter than most but it still doesn’t help this device. |
You think you're winning this game? You don't even know the God-damned rules. But don't worry, I'm gonna teach 'em to ya..
AR Sponsor