Sar4937, I thought "glocked" brass is applicable only for .40, I was having issues with 9x19. I guess the most logical explanation been stated by ArchAngelCD - too much crimp, kind of makes sense to me, round goes to deep because it can't catch on the brass in the chamber, following banging might have "expanded" the throat of the case bringing it to spec, so subsequent attempt was successful...
What dies are you using? Specifically how are you crimping?
As I mentioned above. if it is the LFCD it is not your crimp. it will not over crimp a taper crimp.(unless you have your seating die set wrong and have it crimping also)