I have a 4 5/8th 357 Mag/9mm myself. While the 357 has the edge on accuracy I think I’ve put more Winchester White Box 115gr FMJ 9mm through it than .357 Mag or 38 Specials. But, at $40 per x100 Remington 125gr JHP 357Mag, $25 per x100 Winchester White Box 130gr FMJ 38 Special, verses $18 for x100 Winchester White Box 115gr FMJ 9mm. 9mm is the choice for plinking, if you do not reload. I reload for every gun I own, except the 9mm’s, mainly because I can buy a hundred loaded rounds cheaper than the components to reload 9mm. If I ever do start reloading 9mm I’d taper crimp with a Lee Factory Crimp Die. The BH Convertibles are touchy when it comes to chambering reloaded auto rounds in the 9mm or 45ACP cylinders.