Re: anyone use HP-38 for 9mm or 45acp
HP-38 is Hodgdon's Winchester 231. I think Winchester makes it for them (???). Hodgdon, I believe, makes no powder themselves but buy from powder manufacturers around the world. Recently they bought some powder companies but the name on the bottles is still the original companys'.
I use either in 45 ACP all the time. I load them at 5.6 grains for 230 gr RN FMJ bullets. Works in my 1911, my CZ and my Witness just fine. HP38 (alias for Win 231) is a universal powder for most handgun cartridges, both big and little. At least that's the way I use it. It minimises my powder stores, plus it works well in all cartridges that I have tried it in.