@ny32182 - I know a lot of guys ignore the advantage and hate the idea of AGB’s, but personally, I almost never shoot an AR without one, and certainly don’t go suppressed without one. A couple clicks on a detent screw block and you can swap in and out of suppressed fire, swap from full pressure rounds to reduced loads, run heavy or light reciprocating masses at your will (aka swap to a different lower with a different buffer weight).
Well worth the confidence, in my book.
While that’s normally true I don’t believe there’s a setting on an agb that would result in popped primers from factory ammo. So something else is going on
While that’s normally true I don’t believe there’s a setting on an agb that would result in popped primers from factory ammo. So something else is going on
my point is changing the gas is a minor tweak. like changing the buffer weight. the AR is running on the ragged edge of pressure with factory ammo and adding a suppressor puts it over the edge. sure, putting an AGB in there might pull it back so it's not popping primers, but it's like like it puts it back comfortably into the middle of the operating range. it's basically just masking a symptom.
that's dangerous because someday a little rain or dirt or something in the chamber that would cause a normal rifle to maybe pop primers, is going to cause this one to kaboom.
There aren't really other pressure signs though: No cratering or pierced primers, visually screwed up case heads or splitting, etc.
B) You mention other rounds dribbling out of the port - which, as I mentioned above, is a symptom of a weak extractor. So a weak extractor with an early unlock won’t leave significant scoring on the rim which one might expect.
C) Primer cratering can’t happen in a condition where primers are popping. Cratering only happens when the primer is held hard against the bolt face with an excessive pressure flowing the primer into the pin bore. Cratering isn’t a good indicator of pressure anyway. Equally, piercing only happens when the case is held against the bolt face and FP, holding the primer hard enough against the extended pin during the peak pressure. Blown primers happen when the bolt is withdrawing away from the round, leaving room for the primer to escape.
I'm almost sure that the primers are just not very tight in this batch of ammo, and the increase in back pressure of the can is somehow creating a situation where they are getting pushed out.
This isn’t a thing. Primer tension in the pocket is never fighting the pressure of the round - primers are ALWAYS pushed out by the firing pressure, but the cartridge is then slammed backward to reseat onto it. We’re pressing primers into and out of place with a few pounds of pressure, and the firing pressure is 50-60kpsi... not even close...
What you’re seeing, in this case, is the primer is getting pushed too far out and the case is not moving with the primer, not secured to the bolt face.
We know his is happening at the BACK end of the combustion cycle, because your magazines aren’t getting blown out of your rifle and case-heads aren’t getting blown off. So what’s happening for you: the primer is pushed out of the case against the bolt face during primary ignition, the case is thrust backwards to reseat the primer as the bulk charge is ignited, the case expands to seal against the chamber, the primer cup expands to seal against the brass, then when the bullet passes the port, the gas impulse overpowers the action mass inertia, opening the bolt - BUT - the case is still under excessive pressure and holds onto the chamber wall, while the bolt moves rearward. Because the case is held momentarily in the chamber and the bolt is moving away, pressure pushes the primer back out of the case.
Wouldn't this result in a failed extraction?
If I understand correctly this only happens with the Radway ammo. Everything else runs fine.
If true, I'd say the simplest answer is it's the ammo.
Wouldn't this result in a failed extraction?