LC9 quits firing with UMC ammo

[retired2006]

Hi, I have my own LC9 on the way, but I was lucky enough to have a friend who had a NIB LC9 that needed broken in. I offered my help, as I wanted to try one before purchase.
I fired CCI Blaser aluminum, Fiocchi, Winchester white box, and Rem UMC thru the LC9 and was surprised with a problem when using the UMC ammo. Fired about 10 rounds and started having misfires, primers showing very light hits. The problem turned out to be that the UMC ammo primers were flowing back in into the firing pin hole, and after ejection, leaving a tiny bit of brass in the firing pin hole, after a few rounds, enough brass built up in the firing pin hole to cause the misfire. A simple manual pushing forward of the firing pin cleared the brass. A look at the fired brass showed the problem.

I must admit that this was a first for me with the UMC ammo, or any ammo for that matter, but does show the importance of firing a box or two of ammo thru any new gun. I always fire at least 50 rds of any carry ammo thru my guns.

My own LC9 will be here soon, I was lucky to have a friend who let me try his before I bought.

 

[Cheesewhiz]

UMC has a long (forward) ogive bullet for 9mm factory ammo, the bullet is probably in the rifling of this gun when the round is chambered. That's not good at all, have your friend pull the barrel out of the gun and insert a UMC round in the chamber. If it sticks or cannot be spun when fully inserted than this is the issue here. A bullet into the rifling will elevate the chamber pressure beyond limits, causing the distorted primers that you see. This is dangerous and not good for the gun, have your friend stop using these rounds in that gun.

 

[retired2006]

Update on the above issue.
I rec'd my own LC9 weds, and tried it out, using the same ammo as I used in my friends LC9. The every same lot number UMC that caused the FTF in my friends LC9 worked just fine in my LC9, it now appears this is an issue just with his gun.
This shows the need to fire the different brands of ammo in your carry pistol, and that guns are individuals just as we are, what works for me may not work for you.