Gunsmithing 308 Chamber Polishing

[longshooter70]

I recently fired my Rem 700 PSS DM and had a hard time extracting the brass. Once I got it out, the brass had some minor pits in it. I took it home and cleaned the chamber really well and it looks fine. Fired again, same thing. I've got about 800 rounds through this rifle and have never had a problem. I clean the chamber, lug recesses and bolt after every firing. I use clean patches to wipe out the chamber really well. I normally clean the barrel when I notice accuracy starts to fall off.
I use Imperial Case Wax for sizing and wipe each round off with a clean towel after sizing.
I've checked head space, good to go. I looked in the chamber the best I could and I see no abrasions, rust, pits, etc. The extractor and ejector look fine and it will extract unfired brass well.
I'm stumped. Probably something simple I'm overlooking.
Any suggestions would be very much appreciated. Thanks...

John

 

[stangfish]

Re: 308 Chamber Polishing

Have you tried some very fine scotchbrite wrapped on a brass bore brush?

 

[LRI]

Re: 308 Chamber Polishing

If your having troubles with reloads and it works fine with new stuff maybe its time to do an oil change on your brass.

Overtime brass work hardens and doesn't resize the way we'd like. If it's still relatively new maybe try full length resizing it.

The "pits" you describe can certainly cause troubles. A ring may be present in the chamber that brass will flow into. This creates a mechanical lock, much the way epoxy flows into an area and locks a receiver in a stock, and will make extraction difficult.

If its a new problem on a proven gun though, I'd look towards changing out your brass.

Hope this helped.

C.

 

[longshooter70]

Re: 308 Chamber Polishing

It will extract a new, unfired piece of brass or one that has been resized but not a fired case whether new or reloaded.

Yesterday when I read Chad's post about the under size Win brass, I went and measured mine. It measured 0.464" at the web and 0.465" at the case head. I called Winchester and asked if they had a problem recently with their brass. The rep there would not confirm nor deny but he is sending me a shipping label to send back my brass to them and they are replacing it all, no charge.

The brass I'm having problems with had only been loaded twice. I use a Forster Co-Ax press and Redding dies. I bump the shoulder back 0.002" when I re-size. I then chamber every round I load to make sure it cycles before I take it to the range. Nothing worse than getting to a match or the woods and having a round not chamber.

I did take some fine Scotch Brite on a brush and run it in and out of the chamber this last go round.

Thanks for the advice Chad and Stangfish. Maybe this will work it out.

 

[former naval person]

Re: 308 Chamber Polishing

If you are just "wiping" the sizing lube off, you may have "plated", for lack of a better word, enough lube into the chamber that combined with some gas leakage has hardened and appears to cause pits in the brass. The cleaning may cure that problem for you.

 

[longshooter70]

Re: 308 Chamber Polishing

former naval person, I hope you are right. I've cleaned the devil out of it and it seems ok. I'm going to shoot it this weekend to verify. I have some new Lapua brass I'm loading now. I've been really happy with this rifle so far.

 

[stangfish]

Re: 308 Chamber Polishing

Let us know how it worked.

 

[IkeEng]

Re: 308 Chamber Polishing

Did that resolve your problem?

 

[longshooter70]

Re: 308 Chamber Polishing

New and re-sized Lapua brass functions flawlessly. New Winchester brass hangs in the chamber horribly. Once it has been shot and re-sized, Winchester functions albeit not as easily as the Lapua. The problem is the new Winchester brass being so undersized to begin with.

Thanks for asking...