Sharper2112
Member
- Joined
- Jan 30, 2017
- Messages
- 79
So I’ve been reloading 9mm for several years now ever since I got into IDPA/USPSA. I shoot a P320 X5 Legion and use Blue Bullets .356 125gr Truncated Cone. I seat to about 1.115 COAL. I consistently have a high percentage of plunk test failures; usually about 10%. I typically will shoot that 10% in a practice session and rarely will one of those rounds not cycle. What I have noticed is on the rounds that will not plunk the measurement at the case mouth is .380-.383, while the 90% of rounds that do plunk measure .377-.379 at case mouth. My question is what could be causing this apparent bulge at the case mouth on 10% of my loaded rounds? I’m kind of at a loss