Looks too easy to be true, once you have the tools made.   

Thanks.

I followed the directions on this thread on making 25-20 ss brass from 223 cases.  Everything worked as discussed but now I need to thin the brass at the neck.  What is the best way to cut the brass at the neck?  The brass out of the sizing die is tapered nothing is straight so open to suggestions.  Thanks for your help making cases.  Charlie

I'm assuming you want to thin the neck walls.   

The NECK portion should be within a thou or two of being straight, so O.D. turning is easiest.   But I'm concerned that you should say it's tapered.    Have you run an M-die type expander in it yet?

Can I also assume that you have a lathe? 

Phil

I have decided to make a bushing to fit over the neck to force it straight then inside ream the neck to get the brass to the correct thickness.  Since these cases were made from .223 rem. the necks are formed from the shoulder area of the .223 brass and is varying thickness.  The bushing will also keep the brass from expanding when reaming.  I believe this will solve the problem.
Charlie

cheatin_charlie wrote on Oct 18^th, 2023 at 8:15am:


If you can keep the reamer running concentric, this is the best, if not the easiest, way. 

The benchrest guys talk about a "doughnut" forming at the transition from shoulder to neck, when OD turning.  Reaming avoids this altogether.   

The Wilson system reams, for what that's worth.

At one point, after I got my "big" South Bend 10" Heavy running, I considered a pressing a case into a shouldered drill bushing, (McMaster 8492A176) chucking the assembly in a collet, and boring the ID out with a boring bar.  The bushing and collet would keep everything concentric, so the neck walls would be uniform. It would be slow, but you'd only have to do it once.  Using a shouldered bushing would give you something to grip when extracting the case using a reloading press.   

Thanks Brian!   If (and it's a big if) it's actually in decent condition I plan to convert it back to .25-20.  That old brass really isn't up to Lovell pressures.  Never was, which is why there's so little original .25-20 left.  The Lovell guys were running it as high as 50,000 psi, and were getting just 3 or 4 loads out of it before it started failing.  Reverting it back to .25-20 will only subject it to pressures in the 10-12 kpsi range, and it should last a while.  Meanwhile the converted .223 will serve Lovell shooters much better.

I've actually got plenty of both, and being so badly handicapped now I never get the Lovells out anymore. So if it does convert back OK, I'll put it up for sale on the ASSRA forum.   People need it, as you well know.