I have an older Sierra manual, It showed a load for a .38 special for SR4756 powder of 8.7 grs with a 125 XTP and a load of 8.3 with the 158 xtp. On the Hodgdon site it showed a max load of 6.5 gr SR4756 with the 158 xtp in the .357 chart. Seems very strange that the Sierra .38 special load is quite a bit more than the Hodgdon .357 with the same powder. Anyone have any information on loading 8.5 grs of SR4756 in a .357? With the discrepancy in the two I don't feel like damaging my S&W Model 19 or me if there is a problem with that load. I loaded up a couple hundred rounds and don't want to have to take them all down if I don't need to.
Here's a site that has IMR data that you can download: http://www.imrpowder.com/pdf_reload.html I think it is the last version of IMR's Handloaders Guide. You can download rifle, pistol, or shotgun or all three. Using Remington cases and primers it says: .38 Special 6.1 grains with RP 125 sjhp--925fps--15900 cup pressure 5.2 grains with Hornady 158 jfp--705fps--15300 cup ________________ 357 Magnum listed: Rem case-RP 5 1/2 8.6 with Rem 125 sjhp--1180 fps--35800 cup 7.5 with Rem 158 gr sjhp--940 fps--35700 cup IMR's warning is to reduce 10% from the above and work up. Good idea to check several sources when there is questionable data. SR4756 is pretty fast to use in .357 Mag loads.