Bullet seating causing problems?

[HUNTER2]

Double strike primers- was loading some 300 rds and had some rounds that took 2 strikes to fire. new brass - good and tight primers- primers replaced with hand tool with no damage- 180 Speer backwards- 165 forwards, 200 gr cast- tried different primers- once fired brass---still having one now and then. Then I noticed one with a level primer! When primed, they were all checked to make they were below level.. All primed pieces checked ok....Tried loading some more....found another one....these are not compressed loads....Am I compressing the air in the case so fast it is moving the primer enough to equalize pressure? Loaded up another 100 seating the bullet slowly with no problem! Now trying the other variables with the slow seating and so far ok. Had been blaming it on a weak spring of questionable primers.. I load for 357 up - this is a new one on me!!! Anybody else?

[Malaga]

Hunter... my only issue has/is with CCI BR primers... my CZ is in 223 and I have not loaded any to check if they function in it...what firearm are you using? whose primers?

[HUNTER2]

It has happened with Win.,Fed.,Rem BR, 2 brands of spp's...LC brass 04-07-08, new Win. 223 cut down, and remanufactured 223 from BH's...If I seat the bullet slowlllly it workes every time! TC Encore and Savage....But you can actually feel the diference with the primer!!! OK - When a round is loaded, does the air inside the case always stay compressed, or does it slowly return to present altitude pressure? Any round? Sure the larger the case for bullet size it would be less - Whispers ( big into small ), are we pushing it? The longer I reload, the less I realize I know! When all I played with was the 7 mag. without a chro. life was much simpler with a bullet a lot slower than I thought it was.....It has me stumped.....

[Alleycat]

I had a guy drop off a Remington 700 with the same problem. It took me about 10 rounds to get it to misfire. What I found was gunk in the bolt. The firing pin shoulder was hitting the gunk and not dimpling the primer deep enough. What had happened was a bad pin had started piercing primers and letting gas into the bolt. He had changed the pin but did not clean the inside of the bolt. This may not have any thing to do with your situation, but most of the time it's something simple.