Clicky bolt lift

[JarheadAZ]

This could be a headspace issue. Wherever you see shiny new marks on fired brass, you are viewing the direct consequences of stretching brass getting polished under case pressure as it rubs against the chamber and bolt face surfaces.

That shiny part is caused when the case and chamber expand and contract, and the shiny area is where A) the brass is thinnest, and B) the brass expands the most.

Headspace is directly related to the stretching which induces case head separations. Minimizing headspace likewise minimizes stretching.

It should take no stretch of the imagination to see where this is leading.

Greg

 

[RonS]

Just a thought but could the chamber have been cut with a reamer to make a full length die?

 

[BoydAllen]

First of all, a gunsmith had better be looking for chamber runout that is a lot better than five thousandths. I would expect more like 20 times better than that, something like 2-3 ten thousandths. Secondly when a chamber is polished at the back of the body, the gunsmith sets the barrel up in the lathe so that the barrel is well supported and the chamber is rotating on it axis. In that situation gentle polishing with a stick and some abrasive paper should not be a problem for concentricity at all. It does take some skill, but is is not vodoo gunsmithing. Once the chamber has been corrected your problem should be over. I like to keep things simple and direct. Either replace the brass or fix the chamber. Which you choose would depend on how much brass you are trying to salvage, and the cost of the chamber work.