I’ve got the Henry in 357 mag. It’s amazing how many ideas pop up in my tinkering thoughts times.
1) leave it be.
2) thread for a can.
3) ream to 357 Maximum. (I have enough brass).
4) 357 Bain&Davis. (I have a form die).
5) 358 Win.
6) ???
I’m still at step #1. 😆
Don't run 38sp in it, you'll be disappointed. That is all I have to say about the henry 357 single shot.
