davkrat
Well-Known Member
Been reading up on loading for the 7mm Rem Mag. I worked up a load for my brother's 7mm based off the Hodgdon online data for 150 grains using H4831. The Hodgdon data listed 59.0-62.0 grains and using Nosler's suggestion to stop at mid level loads for the E-Tips I loaded 59.0, 59.5, 60.0 and 60.5 grains. 60.5 grains gave an average velocity of 2844 fps and SD of 8.0. It also shot the attached 3 shot group at 100 yards. Reading others speeds they're getting with 150's recently I realized that 2844 is barely using the capacity of the 7mm Rem Mag.
Just now I pulled up the Nosler and Hodgdon data again. For some reason the original Hodgdon data I used for 150 gr. partitions max's out at 51,100 psi pressure? Hodgdon lists data for 150 grain Barnes with 6 grains more powder and 60,200 psi as max??? Nosler for 150 grain bullets lists 61.0-65.0 grains of H4831. Going to try up to 63.0 grains as max with the E-Tips and see how they shoot. Hoping to safely get the E-Tips up to 3050 fps or so. An extra 200 fps is pretty significant.
Why the huge discrepancy in maximum charges and associated pressure? 62.0 gr, 65.0 gr and 68.0 gr. are the three listed maximum I found for H4831. Almost sounds like I could use 62.0-68.0 as a load range and stick with 65.0 as max for the E-Tips. Of course we'll work up but if 63.0 or there about gets us 3050 fps we'll be happy with that. For where we hunt that should maintain 2000 fps velocity out to 700 yards which is more than enough for us.
Just now I pulled up the Nosler and Hodgdon data again. For some reason the original Hodgdon data I used for 150 gr. partitions max's out at 51,100 psi pressure? Hodgdon lists data for 150 grain Barnes with 6 grains more powder and 60,200 psi as max??? Nosler for 150 grain bullets lists 61.0-65.0 grains of H4831. Going to try up to 63.0 grains as max with the E-Tips and see how they shoot. Hoping to safely get the E-Tips up to 3050 fps or so. An extra 200 fps is pretty significant.
Why the huge discrepancy in maximum charges and associated pressure? 62.0 gr, 65.0 gr and 68.0 gr. are the three listed maximum I found for H4831. Almost sounds like I could use 62.0-68.0 as a load range and stick with 65.0 as max for the E-Tips. Of course we'll work up but if 63.0 or there about gets us 3050 fps we'll be happy with that. For where we hunt that should maintain 2000 fps velocity out to 700 yards which is more than enough for us.