The Henry Big Boy owners manual states that only 158 gn .38 special rounds loaded to .357 Magnum length will function reliably in the rifle.

I know from experience that 148 gn PHBWC rounds do not feed but jam up on the feed ramp.

100 gn LRNFP Cowboy bullets loaded in .38 special cases also jammed up. When loaded to .357 length (both in Speer nickel plated brass) they were not as accurate as the same load in .357 cases (10.5 gn AR2208, the “replacement” for Hodgdon’s “old” H4227).

In the end I went with the .38 special load in .357 cases.

Cheap to reload, mild to shoot and accurate.