doublegunshop.com - home Forums General Discussion Classic & Custom Single Barreled Sporting Rifles @ doublegunshop.com H. Barella 7x57 Mauser - Tight Chamber?

Have had some luck lapping the chamber for cartridges that are just slightly tight at the web.
Fine valve grinding compound on the cartridge web only and rotate by hand.
Probably no more than .001-.002" with this process.
Chuck

If a marked up case shows tight in the body you can push the case in a bit more putting a washer on top of the shell holder, knocking the sized case out with a rod.

This for size test only, push it in further likely to set the shoulder back . May give a clue to what's tight though. . Dies will size hollow brass won't reduce the diamater soiid brass at the base . Tight at the base driving in further likely cause a stuck case very difficult to hammer out.

Way I found out my 25 Kraig was base tight cut a case in half chambered the bottom, tight with little body and no neck. I thought it was the neck, having sized the cases down from 30/40.

It's a puzzle,have to keep at it until solved.

Boats

You can push the 7x57 deep(er) into a standard 30-06 FL die (if you happen to have one around) and not set the 7x57 shoulder back.

Using a LR Primer Pocket Swage replacement for the standard shellholder makes a nice pusher for the case in this process. It is flat, allows the case to be pushed as deep as possible into the die and the p/pocket swage punch keeps the p/pocket on the case from deforming/downsizing as a result of the solid base swage work.
A suitable sized steel washer is of course much more likly to be on hand in most reloaders shops and works well too. Just check the primer pocket after the work and make sure they didn't reduce in size a bit. The matr'l has to go somewhere.

Using the FL die you can swage the solid base down but you need a very strong linkage advantage press to do it and only in very small increments of a couple .000 at a time.
Don't skimp on the case lube and use a knock out pin to punch or press (prefered) the swaged case back out.
Don't try to use the standard shell holder/case rim method to withdraw it when doing this. It'll shear off just about every time.

You may have luck using a 45acp FL sizer also. They are usually about .467/468 at the base.
Plus no issue with the case shoulder above.
A carbide sizer die may crack the carbide 'ring' inset into the steel die body if you use it for this swage process.
I'd use a standard old steel FL sizer for the try.

Kutter,
Using the primer pocket swage is a good trick, thanks for the idea, I had been using a "shop made" blank, with a flat top, then recutting(if necessary) the primer pockets with a "uniformer".
Ken, don't forget to remove the expander assy. before doing this. Don't ask how I know to do this.
Mike