When I’ve taught people how to shoot, I start them off with either .22 or really light .38 loads in my 6” King Cobra; makes for very light recoil since it’s a massive gun. I think .38’s in a henry would be great, now that you mention it; I’m too old to beat the piss out of myself shooting these days, been there, done that :-)
38 Specials in a longer barrel are nice in that they also come out faster than with a hand gun. I think .357’s come out of a hand gun between 1200 and 1250 fps and out of a 16” barrel around 1800 fps. Not sure how they would come out of a longer barrel like in a Henry, but surely a bit faster than with a hand gun. I’m 65 and don’t need to beat myself up to enjoy shooting anymore but it’s nice to have the more potent option....since most .357 weapons will also work fine with 38 Specials, it makes for a good choice.