Groove diameter should be .251” so a bit tight for .25-20.

The cases can be formed from .22 Hornet ( rims will need to be thinned) and cast .25 ACP bullets are the right 50 gr. weight and .251 diameter.

If it is not rusted out why not keep it as it is?

If the bore is rusted out then re-tube to .22 Hornet ( probably need to bush firing pin) or bore out to .32 S&W Long, .327 or .32-20.

Last edited by Parabola; 09/26/22 11:10 AM.