Pierced Primers in Winchester .223 USA 55 FMJ

[drvrage]

Hi Folks,


I would appreciate any input you folks have on a situation I discovered on the long weekend when trying out my "new to me" XCR. (P.S. kickass rifle)

I was shooting winchester USA brand .223 rem 55gr. FMJ and while I was collecting brass (I'll reload once I get a press, but aimpoints aren't cheap) I noticed that about 2 of 200 brass had pierced primers. The rest of the brass didn't seem to have over-struck primers. They looked just like the primers out of my .270 win that never pierces primers. Now I've read the Lyman reloading manual cover to cover a few times, so I'm already pretty cranky about having pierced primers mucking up my bolt face.

I was hoping to hear from my fellow CGN'ers if anyone else has noticed this. Does this really happen from time to time in general? Is it the cheapo USA brand of ammo? Could 2 piercings out of 200 be my rifle? Any feedback is appreciated.

 

[Shelldrake]

Might be your rifle. You may have a tight chamber. One of my ARs has a tight chamber and will pierce and blow primers from MilSpec ammo, but eats winchester white box ok. Are there any other signs of high pressure?

You should also examine closely the tip of your firing pin for gas erosion.

 

[drvrage]

Terra from Robinson arms says that the firing pin hole in the bolt face needs to be chamfered a bit. She offered me a new bolt or to repair the old one. I said If I'm going to chuck the old bolt anyways, I'm going to try the chamfering myself with a Dremel tool. I did it and I'll post here with pics and results later.