I have a 10.5" RRA SBR.
I shot steel and brass through it and have no issues with a std buffer, unsuppressed. Suppressed it shoots steel cased fine but brass does not load the next round.

I converted to a H2 buffer and shot it...It shoots brass and steel just fine supressed, but unsupressed it did NOT like the brass. The rounds failed to eject before the next round chambered. I got an empty shell lodged nearly EVERY time I fired.

What do I need to do to shoot both steel and brass reliably unsupressed and supressed?

The steel ammo is 223 55gr FMJ, the brass is Federal American Eagle 55gr FMJ .223 as well.

Thanks.


If I have to finish off my steel and not go back to it I am fine with that BUT the problem again is NOT with the steel, its the brass that has always given me the problem.

Sounds like it's over gassed with the suppressor but the steel cases are under powered enough for it to cycle reliably. Have you tried an adjustable gas block? If no, that would be the real fix, if not you can bandage it with an even heavier buffer and/or buffer spring.

I was thinking a heavier buffer like an H3. What type of spring would you think would fix it?

The problem isup cycles the cheap under pressured stuff fine and the quality stuff supressed (max amount of pressure), its the unsupressed tha thas less pressure and in the middle of all scenarios I shot in that had the issue. So over pressure didn't seem to be an issue and neither did under pressured. It was the middle of the road pressure that was the issue.

Try the lock back test. Shoot a magazine each of every combo of can/no can and brass/steel one at a time in a magazine. If it always locks back, you aren't under gassed. 10.5" uppers with cans are notoriously overgassed and it causes the same problems as undergassing, except for locking open the bolt on empty mags. If it is overgassed, put in a H3 buffer and a springco blue spring. Maybe even the red spring. Use a BCM bolt upgrade kit while you're at it and clean the chamber very well with a chamber brush. Get an adjustable gas block if all that fails.

This sounds like the extractor is losing control of the case.  Does your bolt have an O-ring, buffer insert, or XP extractor spring?  If it doesn't have an O-ring I would add one.



 I would also check the ejector spring.  With the bolt face towards the ceiling, place an empty case under the extractor and cam the ejector flat.  If the extractor breaks loose, then you definitely have an extractor problem.  Once the case has fully compressed the ejector, let the case go and see how far it flies.  IME a good ejector should throw the empty case around 6ft when this test is performed from chest height.



 

change extractor/spring first.

I did change the extractor spring and added an O-ring.

I tested 3 rds of brass .223 all fired, ejected and chambered fine. A 4th rd chambered fine as well
I again tested by firing 3 rds, all fired correctly and 4th rd loaded.

Soon I'll take it to the range and fire a few magazines full.