32-20 to 25-20

[Rapier]

If you want to reform brass, especially bottle neck cases, you need to start with quality brass and use quality dies, plus you always clean, anneal and size the brass before you even think about reforming the brass. No short cuts, do it right.

I studied these two cases at length before deciding to build the gun as pictured. The 25-20 started life as a necked down 32-20. However, today, the 25-20 has different set of specification for the base and body, from the 32-20. If you analyze necking the 25-20 to 30 cal, you will basically find that you get an elongated straight wall 30 carbine with a rim. I use 32-20 and 25-20 brass both to create this cartridges. I use a 25-20 FL sizing die, cut off at the shoulder, then a 25-20 FL sizing die , then a die with 308 expander ball. Basicly, I form the 32-20 all day long to a 25-20 or the reverse then into a 30x25-20.

The idea was to create a revolver that used 30 cal rifle bullets at 150+ grains and 1,700 fps to take advantage of the BC of the rifle bullets, for distances of 200 meters with the terminal momentum suffcent to take down a 70 pound T-1 ram.


Illustration of the results. With 150s to 200s, you get this, for a 308 Revolver, which I built, made the barrel and cylinder inserts from a new rifle barrel blank, the long barrel nut, long barrel wrench, reamed the cylinder chambers on a 445 cylinder, chambered the cylinder chambers, etc:

[bjmurata]

I'm fortunate in that I do have a modest stash of 25-20 brass on hand. That being said I do reform 32-20 to 25-20 to add to them on occasion.
I have had good results running the 32-20 brass into a file trim die, usually in 3 or 4 stages at a time. I take my time and it works well for me.

[TacomaPete]

I was lead to believe reforming 32-20 brass to 25-20 is as simple as just running the 32-20 brass through the 25-20 sizing die. Well I can’t even get them to start without collapsing the mouths or necks of the Starline cases. Tried every type of lube I have but no luck. My 25-20 dies are from Lee. Is there a transition die I should be using?

I just saw your post.
Did you ever get your case reforming sorted? I had two intermediate "dies" made, one at 7.5 mm and the second at 7mm using a couple of 7/8 x 2 1/2" bolts. Once they were drilled and the mouth chamfered the inside was highly polished. My gunsmith did the work but I would have been more than capable of undertaking the work if I had a lathe.

To form I used a dab of case forming lube on the inside and outside of the case mouth. After the intermediate steps I put them through the .25-20 neck sizing die and used them with no problems. In fact I still have 98 loaded rounds in my gunsafe and no rifle to use them in.