Ive had a 25-20 (Win.'85LW), two .257Bobs and last year got a 25-35 H&R stub barrel from a forum member here. The standard twist for the 25-20 is 1:14, which limits you to about 90gr. bullets due to length and stabilization. Yes, you can push jacketed faster to help overcome this, but it is hard to really get enough velocity for a marginally long bullet or to avoid leading with cast bullets. A hundred years ago the match shooters with .25s used a faster twist to use the favored 100ish gr. bullets. Ive just been playing with the fast twist 25-35 again and it shoots the low velo 87s as well as the Win. did (just traded it off) and I have the choice of using the much better BC long bullets and a variety of velocities. It doesnt seem to be fussy.
If you do a 25-20 you might consider using a std. 25 CF cal. barrel (or liners are available too) with something faster than that old 1:14. Even in 25-20 I dont see a downside in this. Then if you wanted to rechamber in the future to 25-35 you would be all set.
With the 32-20 size you might be better off chambering to the newish .327Fed. The case capacity is similar and since it is an overlong 32.S&W Long it would be an easy cartridge to live with using carbide dies, etc. I have a 32-20 revolver so I know the shortcomings of this cartridge for reloading.
Another approach here is to use the 30-30 chambering with the lighter weight bullets. I use 115-130gr. and duplicate 32-20 ballistics with success. Those loads for fun, varmint, etc. and the full load for deer and black bear gives a very nice sporting combination.
