Mr_Flintstone
Member
When I first got started reloading, I bought some IMR 4227 for my M1 Carbine reloads. It works perfect for this using the data on Hodgdon (because they list the same loads for H-4227 and IMR-4227). I contacted Hodgdon when I started with the M1 Carbine, and they said that H4227 was no longer made, and I could use data from either powder, just start at the low end and work up. That made sense then. I have also heard that IMR-4227 is what used to be H-4227, and the old IMR-4227 is no longer made. I honestly have no idea.
My problem is that I have recently started using it for reloading .357 magnum, and Hodgdon doesn't have loads for all of the bullet styles/weights that I have. I can find most of them in the manuals I have, but there seems to be a wide range in load data between some H-4227 and IMR-4227 for same bullets. On some, the high end of one is less than the low end of the other. Some manuals only list one or the other, but not both.
In comparing modern (last couple years) IMR-4227, would it be closest to the old H-4227 or IMR-4227? Which load data would you consider safe for the new powder?
My problem is that I have recently started using it for reloading .357 magnum, and Hodgdon doesn't have loads for all of the bullet styles/weights that I have. I can find most of them in the manuals I have, but there seems to be a wide range in load data between some H-4227 and IMR-4227 for same bullets. On some, the high end of one is less than the low end of the other. Some manuals only list one or the other, but not both.
In comparing modern (last couple years) IMR-4227, would it be closest to the old H-4227 or IMR-4227? Which load data would you consider safe for the new powder?