under gassed

So I've got an AR-15 pistol with a 10" barrel, where the bolt won't lock back on an empty magazine. It's chambered in 5.56, but I mostly shoot 223 out of it. I also have an AR-15 rifle chambered in 5.56 through which I also mostly shoot 223 out of. Both ARs have carbine length gas systems...

Hey guys. My last 2 guns were a 10" 5.56 AR pistol build, and a Tisas 1911a1. Took them both to the range today and had issues with both. To stay let me say, this it's my second AR build, but my first pistol build. It's an Anderson lower with Anderson LPK, SBA3, 3oz carbine buffer, Bear Creek...