I have reloaded a lot of 9mm shells through my Lee Load Master Press. I reloaded 20 and was very happy with them. I used longshot powder and Remington 1-1/2 small pistol primers. Very happy with the groups.
I couldn't find the Remington SPP 1-1/2 so I got some Remington SPP 5-1/2 primers.
About 1 out of 10 shells fails to go off.
It appears that the firing pin has just barley came in contact with the primer when it doesn't go off.
I have tried re-feeding the lightly stuck primer back into the gun and sometimes it goes off and sometimes it doesn't.
I have read that these 5.5 primers are a lot thicker in the base and this could be causing the issue.
I reloaded with the 1.5 primers and had NO issues with them going off.
A few things should be noted
1- I dont trim pistol brass and didn't know it was necessary to do so.
2- I have NEVER had an issue with this gun and dont
3- My wife's S&W M&P fired these fine with a nice primer strike.
4-my gun fires flawlessly with factory rounds
5- The gun is VERY clean
6- I am crimping the cast bullet (I cast and powder coat my own) into the case (could it be that the bullet is going too far into the chamber?)
To be honest I am new to reloading pistols. I have loaded just a few thousand rounds so any advice would be great.