I know this has been covered but I have not been able to find exactly what I am looking for.

I just bought a brand new M111 .300 win mag. I am planning on rebarrelling the rifle in 7mm Wby Mag. This is the first gunsmithing project I've done, and I am a newbie to reloading. That being said, I am a Mechanical Engineer and have a lot of experience build race engines and other tight tolerance work.

Today I called Lothar-Walther. I am looking at a SS barrel in 9" twist, 28" length, threaded for a muzzle brake and fluted.

When filling out the order form I notice the chamber protrusion measurement. When I inquired, the gentleman I spoke with stated that the proper chamber protrusion for my application was .135". Curious, I went home and measure my casing. The distance from them belt shoulder to the end of the casing (primer face) was approximately .215".

Could this be right?

If I set the headspace up off of the belt (correct for belted mags?) at .002" clearance, this will put my casing shoulder .080" off of the shoulder. Is this right??

Should the chamber protrusion be near equal to the distance I measured? Or am I missing under standing this whole thing.

Also, one the casings are shot the first time, what Is the proper way to set up the resizing die? Should I just have it bump the shoulder back a hair, or not at all?



Thanks for any help guys, this is my first savage. Really excited to see what I can do with this build.