recently i've had an issue with a batch of .223 i'd reloaded. everything was normal. 55 grain bullet with 26 grains of hodgdon varget and a brand new case. primers seated correctly, OAL was normal. but when i chambered the first round of five for my normal checks it failed to chamber correctly and the enitre round was stuck in my AR (mil spec chamber). after getting the round unstuck i attempted to chamber the next round, same problem. immediatly i pulled out my calipers and it seems the caseing did not crimp correctly. i checked against the batch i did prior and everything was correct but somehow this one batch failed to crimp.
can anyone help me figure out how this happened??