I was at the range shooting last night zeroing a couple ARs. The first was an 11.5" BCM SBR that ran perfect.
The second is a newer build and it was having problems feeding using the same 20 round magazines.
I would insert a mag all the way, tug it, release the bolt and it would ride over the top round and not load.
I was having the exact same issue on both 20 round magazines, a Colt one and a Magpul.
I tapped on the mag and messed with the rounds and eventually it would work but then I did get some jams and it would fail to lock the bolt back on the last round.
I was shooting Tula and PMC X-TAC 5.56mm NATO 55gr FMJ-BT M193.
I took it home, tried dummy rounds and live rounds and had the same issue.
I tried a 30 round mag and it worked just fine.
Why would two magazines work fine for one AR but not the other?
I recently swapped the BCG on this and before that the only issue I had was failure to lock the bolt back so I reduced the buffer weight from an H to a CAR.
Any ideas?
This is the current build:
Ballistic Advantage AR-15 Enhanced Lower Receiver
Ballistic Advantage AR-15 ENHANCED UPPER RECEIVER
Radian Raptor Ambidextrous AR-15 Charging Handle - FDE
VG6 Precision Epsilon Compensator - 1/2x28
Ballistic Advantage Performance Series 5.56 Hanson Mid-Length Barrel with Pinned Gas Block - 16"
Aero Precision AR15 15" ATLAS R-ONE M-LOK Handguard - Anodized Black
Geissele Super Dynamic Enhanced (SD-E) Trigger
Aero Precision Lower Parts Kit for AR-15 (Excludes FCG, Trigger Guard, Pistol Grip)
Magpul MOE Slim Line Carbine Stock - MIL-SPEC - Flat Dark Earth
Magpul MOE Polymer Trigger Guard - Flat Dark Earth
Magpul MOE-K2+ Pistol Grip - Flat Dark Earth
Magpul Picatinny Ladder Rail Panel - Flat Dark Earth
Aero Precision Enhanced AR15 Carbine Buffer Tube Kit
Radian Talon Ambi Safety 2-Lever Kit - FDE
Ballistic Advantage 5.56 COMPLETE BOLT CARRIER GROUP, NICKEL BORON