Thread: 4895 vs 2206h

This got me thinking. Velocity and pressure are quite linear within the normal pressure ranges so I gathered up some data for 150 grain projectiles and my calculator. In 1976 Dupont listed 44.5 grains of IMR4895 for 2,780 fps as max. In 2003 IMR listed 45.5 grains of IMR4895 for 2,880 fps. The current Hodgdons data lists 47.3 grains of IMR4895 for 2,920 fps. A big range of both charge and velocity. Using the current Hodgdons data and interpolating velocities for 44.5 and 45.5 grains gave 2,745 and 2805 fps respectively. Cases, primers and projectiles varied but the predicted and actual results were close enough to indicate that powder speed had not changed that much, just the method of pressure testing. The Hodgdons data for the 150 grain and H4895 closely matched the IMR 2003 data.
Regards Grandpamac.
PS. Just spotted your post. For NZ hunting conditions you can probably ignore the temp sensitivity, Just don't leave the cartridges lying in the sun or on the dash of your ute.
GPM.