After firing and ejecting 2 rounds the third round chambered but would not fire. The slide would not move at all. The slide looked to be in the firing position. It is a fairly new gun, has less than 1000rds shot. When the gunsmith unjammed the gun and gave me the round that had jammed, the bullet was at least a quarter of an inch longer than the other rounds I had reloaded leaving me to believe that it was a lack of crimp that caused this issue. I have not fired the gun since then. When I first reloaded these rds they chambered just fine in my gun. Also reading my Speer reloading manual they DO recomond a taper crimp but my Hornady manual said little or no crimp. Hope this helps