01-29-2020, 03:39 AM
Mel,
i'm sure you know all this but here goes:
1. primers have to be seated all the way into the bottom of the primer pocket. do you clean pockets? feel the primers on the rest of the CM ammo. any high primers? are all the rest below flush?
2. you could try CCI34 primers i suppose. but i don't think primer cup thickness varies as much in LR as it does on SR primers. i could be wrong.
3. try a different brand of primer
4. measure the length of the firing pin. is it longer from the stop flange to the tip than is should be? compare this length to the original firing pin length from the original BCG.
5. is the tunnel that the firing pin slides back and forth in, from end to end, gummed up in any way that might have held the FP firmly forward during chambering? i think this was mentioned. is there grit in the firing pin hole in the bolt head that might have wedged the firing pin forward?
6. is the bolt shorter from the bolt face to the end of the tail that the firing pin stop flange hits? this would allow the firing pin to stick out further too. probably have the same affect as a longer firing pin. compare the measurement to your original bolt.
7. did the mfgr forget any firing pin machining steps that might have left more mass on the firing pin than "normal"? does the firing pin look like it has "normal' contours? does it look like the original?
8. did the buffer spring strength go up such that the bolt velocity going into battery is quite a bit higher than before? you said you changed buffer springs. does the new one have a much higher spring constant?
9. is the new BCG significantly lighter in weight than the one you had earlier? that would increase the bolt velocity going into battery too.
so it could be a little bit of a lot of variables.
-tdbru
i'm sure you know all this but here goes:
1. primers have to be seated all the way into the bottom of the primer pocket. do you clean pockets? feel the primers on the rest of the CM ammo. any high primers? are all the rest below flush?
2. you could try CCI34 primers i suppose. but i don't think primer cup thickness varies as much in LR as it does on SR primers. i could be wrong.
3. try a different brand of primer
4. measure the length of the firing pin. is it longer from the stop flange to the tip than is should be? compare this length to the original firing pin length from the original BCG.
5. is the tunnel that the firing pin slides back and forth in, from end to end, gummed up in any way that might have held the FP firmly forward during chambering? i think this was mentioned. is there grit in the firing pin hole in the bolt head that might have wedged the firing pin forward?
6. is the bolt shorter from the bolt face to the end of the tail that the firing pin stop flange hits? this would allow the firing pin to stick out further too. probably have the same affect as a longer firing pin. compare the measurement to your original bolt.
7. did the mfgr forget any firing pin machining steps that might have left more mass on the firing pin than "normal"? does the firing pin look like it has "normal' contours? does it look like the original?
8. did the buffer spring strength go up such that the bolt velocity going into battery is quite a bit higher than before? you said you changed buffer springs. does the new one have a much higher spring constant?
9. is the new BCG significantly lighter in weight than the one you had earlier? that would increase the bolt velocity going into battery too.
so it could be a little bit of a lot of variables.
-tdbru