Carl N. Brown
Member
The hang-up described appears to be that, without the semi-auto disconnect working, the hammer following the underside of the bolt carrier will hang on the bolt carrier, blocking the bolt partially open and preventing retraction with the charging handle.
After reading these questions, I made the point of inspecting two ARs built recently from new lowers plus commercial triggers (one non-adjustable and one with adjustable trigger). Obviously NOT specifically Colt AR15s but AR pattern semi-auto rifles.
I had been asked this week to debug one of the rifles. The assembler had just pinned the adjustable trigger in the frame like he had done with the non-adjustable, thinking he could adjust over-travel, sear engagement, and disconnect engagement at the range (NOT a good idea). The disconnect was not catching the hammer and the hammer was just following the bolt carrier closed, leaving a barely visible dimple on the cartridge primer. Actually the dimple was about what I see from just the inertia of a free floating firing pin. No disconnect engagement meant bang! once, manually eject second unfired cartridge, not full auto. (Taking the time at the kitchen table with the lower and following the instructions that came with the adjustable trigger had everything working as it should).
Looking at the AR M4gery carbine with the non-adjustable trigger group and the large AR benchrest type rifle with the adjustable trigger group, I did not see any way the hammer could hang underside of the bolt carrier. Again, these were not Colt AR15s but AR pattern rifles.
With this adjustable trigger, with the hammer down, the hammer cannot be cocked when the safety is on: if the hammer is down, it will only cock if the safety is off. If the gun is dry-fired or has a dud cartridge, you cannot fully retract the bolt if the safety was placed on with the hammer in the down position. Other than that, I do not see how these two AR rifles could hang-up as described .
After reading these questions, I made the point of inspecting two ARs built recently from new lowers plus commercial triggers (one non-adjustable and one with adjustable trigger). Obviously NOT specifically Colt AR15s but AR pattern semi-auto rifles.
I had been asked this week to debug one of the rifles. The assembler had just pinned the adjustable trigger in the frame like he had done with the non-adjustable, thinking he could adjust over-travel, sear engagement, and disconnect engagement at the range (NOT a good idea). The disconnect was not catching the hammer and the hammer was just following the bolt carrier closed, leaving a barely visible dimple on the cartridge primer. Actually the dimple was about what I see from just the inertia of a free floating firing pin. No disconnect engagement meant bang! once, manually eject second unfired cartridge, not full auto. (Taking the time at the kitchen table with the lower and following the instructions that came with the adjustable trigger had everything working as it should).
Looking at the AR M4gery carbine with the non-adjustable trigger group and the large AR benchrest type rifle with the adjustable trigger group, I did not see any way the hammer could hang underside of the bolt carrier. Again, these were not Colt AR15s but AR pattern rifles.
With this adjustable trigger, with the hammer down, the hammer cannot be cocked when the safety is on: if the hammer is down, it will only cock if the safety is off. If the gun is dry-fired or has a dud cartridge, you cannot fully retract the bolt if the safety was placed on with the hammer in the down position. Other than that, I do not see how these two AR rifles could hang-up as described .
