First time at range, issues afterwords

[pnutty]

Hello everyone, I finally taken my first large frame 6.5cm build to the range and everything worked great. Put 70 rounds through it and no issues functioning but I was puncturing primers. (Indoor ranges aren't ideal but it was good enough for a function test and scope zero)

When I got home and started to clean it, I couldn't remove the cotter pin at all. I had to clamp onto the round part of the cotter pin with the corner of the vise and yank it out that way. Once I got it out I found the pin was bent to hell, I also noticed a few pieces of primers that came out when I finally got the bolt apart. (Primer pieces are at very top of the photo)

From my research, the primer issue is because of excessive clearance between the firing pin and hole. I measured my firing pin hole at .082” and the firing pin tip at .077”, I found that cmmg makes a .08” firing pin for their mk3 model rifles. 

My questions are if the cmmg firing pin will work in my dpms bcg and if the primer cups getting lodged in the bcg are the reason the cotter pin bent.

 

Specs are m5 receiver sets

cmmg lpk

armalite recoil setup

dpms bcg

ba 6.5cm 20” barrel rifle gas length

 

Edited 11 hours ago by pnutty

[98Z5V]

What ammo are / were you shooting?

I blew the pic up, and can see it's Hornady, but what load?

Edited 8 hours ago by 98Z5V

[pnutty]

8 minutes ago, 98Z5V said:

What ammo are / were you shooting?

I blew the pic up, and can see it's Hornady, but what load?

It was a handload, 40.2g of imr4451 over 140g sst. Primers are cci #34

[98Z5V]

High pressure signs, my man.

Try some 140gr Hornady 6.5C Match. Just get a box and try it.