Need infor on .348 conversion

[Roscoe Coles]

I looked through the posts but could not find the data I need.  I am going to be cutting down 100 rounds of .348 for the 45-75 and I have been looking at different pages on the conversion.  I will be doing this on a lathe so I can get a pretty good cut right away.  What should the case length be at the start of the forming process.  2.02 is the best number I can find.  Is this right?  I don't want to ruin 100 cases. 

Thanks

[Sir Charles deMouton-Black]

I tried shortening the case first with a tubing cutter, but almost every one split as soon as I started to expand them.  I had to salvage those ones as 12.7 X 44 R cases for my Swedish Husqvarna cape gun.

I have a series of three tapered expanders from C-H.  Call C-H, they will know what you need. 

http://www.ch4d.com/  on the menu go to "reloading dies", and then "?M? Type tapered Expanders"

Expand the necks very carefully in stages until they are nearly straight.

Cut them with the small tubing cutter to 1.94", or a bit more.

Run them through the sizing and neck expanding stages, with your regular loading dies.

Then I load them the first time with about 65 grains of GOEX 3F, a card wad, and the 457192 (350 gr. FP) bullet.  Subsequent loadings will accept more powder, up to about 75 grains. 

The first firing will leave them at about 1.92".  They don't shorten more than a bit after that.

Final length of the cases I've seen listed at 1.89, but as long as 1.92.  I can't say the first cut at 2.02" is wrong, especially if that was the original unexpanded .348 case.  I'd convert about 5 to 10 cases first, both to get the knack and to find for yourself the length that works.  Fireform your trial lot before going into mass production.

My Chapparal accepts an overall length, loaded, of 2.30 inches.  Most listed oal's are shown as 2.25"

This is the system That I worked out after reading the same posts, by Hobie.  I'm not saying its the only way, "Yer mileage may vary!"

[larryo_1]

Well, as I have mentioned earlier on this site, I cut my 348;'s back to 2 and 1/4 inches, then annealed them and then put in 16 grains of Bullseye, filled the case with cornmeal and put on a beeswax wad and fired them.  After that, I ran them through an RCBS Trim Die and there you have it.  I suppose that there are better ways of doing this but this has worked for me with this caliber and others that I have done this way.  No case loss!  The only other thing worth mentioning is that chamber on my Uberti IS NOT the same as the originals.  I sent a couple of cases off to RCBS and they made my Trim die so that it emulates what comes out of MY rifle.  Still no case loss!  The ONLY case that I have lost was a Bertram that split at the neck the first time that it was fired.  Hope this poop will help you.   

[Dirty Brass]

I made up a hundred @ of .348 and 50 AK. Listened to a lot of people here, and one thing suggested/recommended was annealing after trimming. This seems to have helped with the .348's because I haven't lost a case yet after 2 shootings with them. The 3 step expander dies worked well, but ws a slow process - I was very careful not to stretch them quickly, and some I even did in increments ( same size die) because they were hard to expand. The 50 AK was a lot easier! 

[Jbar4Ranch]

Expand, trim, fire form, anneal, final trim. Some folks anneal at a different stage in the process.

I made a set of five expanders and only had three or four cases out of 250 start to split at some stage or another. As soon as I noticed the split starting, I backed the cases off the expander, trimmed them back to just past the base of the split, and continued expanding. Didn't lose a single one. Initial trimming was done with a tubing cutter. I annealed by chucking each case in a drill press - hand pressure only on the chuck - so I could get even heating with a propane torch, then bringing a coffee can of water up onto the case when I could see the color change. The whole annealing process took about two hours.

I've done a few Remington cases since, and several of the Remingtons developed jagged body splits well below the shoulder upon fire forming. They seem to be harder brass than the Winchester cases.