I've had my JR out to the range a few times now and I keep encountering some recurring issues. Note: I have yet to contact JR Firearms about these. The gun is in 9mm.
The gun occasionally short strokes randomly. This is the most irritating symptom because I can't pin down anything that's causing it. A round will fire, the gun will cycle and eject the spent casing and load a new round, but the hammer will ride the bolt forward and I cannot fire. I need to rack the bolt to #### the hammer, losing the live chambered round and stripping a new one off the mag.
Best I can guess the heavier spring JR came out with to prevent OOB ignitions in rapid fire is the culprit. I also do notice a good deal of resistance in the initial cocking of the bolt which leads me to believe the hammer spring is possibly too strong, or the hammer is encountering a lot of resistance to cocking. Didn't feel unusual while thumbing the hammer with the subassembly off though.
The second problem I'm having is everything loosening up during fire. The stock castle nut loosens and, more worrisome, the cocking knob loosens. Today even the screws on the lower backed out significantly to the point where it jammed the rifle. Probably my fault from the last time I disassembled it but how tight are these supposed to get? I've stripped too many holes and broken too many screws (not in guns but elsewhere) to know you never over-tighten, but this obviously shouldn't be happening. The takedown of the gun precludes using any thread locker.
Obligatory pic of the work in progress. Need an AR barrel nut to get that SIR sitting properly but it feels nice as-is and I definitely prefer the look. Covers the abnormally long barrel and seems much better proportioned. The SIR is currently attached only to the rail on top of the receiver (another set of screws that could do with some thread locker...) and seems to hold on just fine. Waiting for my JR combo wrench to arrive before tackling that big-ass barrel nut. Threaded barrel and flash suppressor are planned, as well as a Magpul ACS stock to house some allen keys.
The gun occasionally short strokes randomly. This is the most irritating symptom because I can't pin down anything that's causing it. A round will fire, the gun will cycle and eject the spent casing and load a new round, but the hammer will ride the bolt forward and I cannot fire. I need to rack the bolt to #### the hammer, losing the live chambered round and stripping a new one off the mag.
Best I can guess the heavier spring JR came out with to prevent OOB ignitions in rapid fire is the culprit. I also do notice a good deal of resistance in the initial cocking of the bolt which leads me to believe the hammer spring is possibly too strong, or the hammer is encountering a lot of resistance to cocking. Didn't feel unusual while thumbing the hammer with the subassembly off though.
The second problem I'm having is everything loosening up during fire. The stock castle nut loosens and, more worrisome, the cocking knob loosens. Today even the screws on the lower backed out significantly to the point where it jammed the rifle. Probably my fault from the last time I disassembled it but how tight are these supposed to get? I've stripped too many holes and broken too many screws (not in guns but elsewhere) to know you never over-tighten, but this obviously shouldn't be happening. The takedown of the gun precludes using any thread locker.
Obligatory pic of the work in progress. Need an AR barrel nut to get that SIR sitting properly but it feels nice as-is and I definitely prefer the look. Covers the abnormally long barrel and seems much better proportioned. The SIR is currently attached only to the rail on top of the receiver (another set of screws that could do with some thread locker...) and seems to hold on just fine. Waiting for my JR combo wrench to arrive before tackling that big-ass barrel nut. Threaded barrel and flash suppressor are planned, as well as a Magpul ACS stock to house some allen keys.
