591 Bolt face craters/errosion?

[Trevor300wsm]

I pulled the bolt out of my 7wsm today. It is a 591 with a WSM bolt face. I noticed 2 craters or errosion marks on the face just outside the firing pin hole. I know this isn't normal. Also, I remember a while back (a few months ago) that I had a couple primers that looked like they had blow-by and one edge eroded away after firing. Im assuming this is all linked together?

The load I'm shooting is 168VLD with 63gr of RL-22 out of a 24" 1:9 Bartlein. Velocity is right at 3,089fps. I get some extractor swipe on my brass, but no bad pressure signs.

1. What caused the bolt face craters?
2.) Is this something that needs to be fixed or is it ok?

 

[clmayfield]

Re: 591 Bolt face craters/errosion?

Yip. Hot gases escaping around the primer and etching your bolt face. There are folks out there who can resurface that bolt face for you. It is generally believed that the etching does not affect accuracy, but you are either over pressure or you need to toss the brass because the primer pockets are too loose. Maybe both.

 

[clmayfield]

Re: 591 Bolt face craters/errosion?

It was Gretan that resurfaces the bolt face. Probably not necessary:

http://www.gretanrifles.com/services/viewEntry.jsf

 

[Trevor300wsm]

Re: 591 Bolt face craters/errosion?

Thanks Carter!!!

Actually I think it's most likely a combo of both, over pressure and loose pockets. The brass has been fired 3 & 4 times and they are pretty loose. I'm shooting RL-22 and I'm going to try some 4831SC and see if I can maintain atleast 3000fps with the 168's.

 

[clmayfield]

Re: 591 Bolt face craters/errosion?

If you are loose after 3 or 4 firings with Lapua brass, you are overpressure. With Winny brass, you are definitely on the edge. With Federal, well... you might be OK.

 

[turbo54]

Re: 591 Bolt face craters/errosion?

Wow. Back 'er down, man.

 

[javy]

Re: 591 Bolt face craters/errosion?

I have had this same problem with a couple of rifles when using Winchester primers. Loads were not hot nor were the pockets loose. Stopped using Winchester primers and problem went away.

Javy

 

[Trovan]

Re: 591 Bolt face craters/errosion?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Wow. Back 'er down, man. </div></div>

Naaah. " If you aren't living on the edge, you are taking too much room"

Everything I have ever read about bolt face etching is that it is purely cosmetic.

Load it up and let it eat.

 

[lonely_wolf]

Re: 591 Bolt face craters/errosion?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: javy</div><div class="ubbcode-body">I have had this same problem with a couple of rifles when using Winchester primers. Loads were not hot nor were the pockets loose. Stopped using Winchester primers and problem went away.

Javy </div></div>

I’m having similar issues with Winchester primers. First time I thought it was a bad lot and tossed the hundred I had left. Recently I had two more small leaks. Relatively new brass and moderate loads. I’m, not impressed.

What brand did you switch too?


OP: My first leak had me worried as well and I called my Smith. He said it was cosmetic. He’s the LE armourer and said many of the Police rifles have circles on the bolt face due to their age and the amount of rounds put through them. Some have been rebarreled more times than he can remember. It can be fixed, but not worth the cost.