I really like my Marlin 1894 .25-20. As others have said, you can form cases from Starline .32-20. I like to have a quiet "critter gitter" load for around the homestead and have been loading it with Trail Boss and an 85gr cast lead bullet. I can get around 1100fps and a load that is as quiet as a .22lr in a rifle. I can also get in the neighborhood of 1200 reloads on a 9oz jug of Trail Boss which comes out to around 75 cents per 50 cartridges. This makes for a very cheap cartridge to shoot when you cast your own bullets. For the cost of primers and powder, I can reload 50 cartridges for only $2.25, you can't even buy .22LR for that any more.
Here is how I do it.
First I start with a .32-20 case and true the mouth with an expander to make it perfectly round, then I run it into a 6.5x55 Swede die with a homemade riser made from a .30-06 case with a steel insert in it, once this is sized I have a rod I made to tap it back out, then the case is annealed, then I neck size in a .25-20 neck sizer, then it is run into a full length .25-20 sizer which forms and pushes back the should while sizing the body at the same time.
The sequence can be seen from left to right. After this you just expand the neck and load it up. It is a lot of work, but it is a fun little cartridge that is cheap to load once all this is done.
(L to R) .32-20 case, - sized in 6.5 die with riser, - annealed, - neck sized in .25-20 neck sizer, - and sized in .25-20 full length sizer
The slight ring you can see near the base of the finished case is from the first batch of 50 that I made with a factory Lyman FL Sizer. This dies squeezes the brass more then I liked so I opened it up and do not have this problem any more. I think that this die is a little tight to begin with and also .32-20 brass is a about 5 thousands larger then the .25-20 which makes the problem worse.