Home Forums Reloading Big Game Rifles 7mm RM + Sierra

If anyone has a Sierra manual, would you be kind enough to let me know the charges shown for the 175gr Sierra Gameking (SPBT) and Ramshot Magnum? And if you are feeling like you have lots of time to kill ( ) then IMR7828 and H1000 too please.

My Ramshot Load Guide Ed III lists a maximum of 70.1 grs. of Magnum with a 175 Nos. Partition for a velocity of 2852 fps. at 58,541 psi. SD is 6. WW cases and WLRM primers. E

175 GR. NOS PART Hodgdon US 869 .284" 3.290" 74.0 2632 49,300 PSI 77.0 2758 56,200 PSI
175 GR. NOS PART Hodgdon Retumbo .284" 3.290" 64.0 2650 45,400 CUP 68.0 2800 51,200 CUP
175 GR. NOS PART Hodgdon H1000 .284" 3.290" 61.0 2567 45,000 CUP 64.5 2692 50,400 CUP
175 GR. NOS PART IMR IMR 7828 .284" 3.290" 57.0 2549 49,800 PSI 61.0 2707 58,300 PSI
175 GR. NOS PART Winchester Supreme 780 .284" 3.290" 59.2 2639 51,300 PSI 63.0 2789 58,800 PSI
175 GR. NOS PART Hodgdon H4831 .284" 3.290" 55.0 2532 45,800 CUP 58.0 2660 50,200 CUP
175 GR. NOS PART Hodgdon Hybrid 100V .284" 3.290" 53.0 2567 49,700 PSI 57.5 2740 58,200 PSI
175 GR. NOS PART IMR IMR 4831 .284" 3.290" 54.0 2540 50,100 PSI 58.0 2710 58,700 PSI
175 GR. NOS PART Hodgdon H4350 .284" 3.290" 51.0 2504 46,200 CUP 54.0 2617 51,400 CUP
175 GR. NOS PART IMR IMR 4350 .284" 3.290" 54.0 2586 52,600 PSI 57.0 2698 58,800 PSI

Arac
Sierra doesn't show data for magnum but 7828 is 62.8 to 64.5 max for 2800and 2900 fps at 3.245" C.O.A.L.
H1000 is 60.7 to 63.4 max for 2700 to 2800 fps at the same length.

Thanks guys.

The 175gr Sierra BTSP gameking is what my 7mm rem mag is shooting. Near Max load of RE22 is right on 2900fps in my rifle. If you have some RE22 you might give it a test.

That'll be the first one I give a shot in my old 7mm Rem Mag. That is a powerful combo right there.

I did work up to 3000fps with re22 and the 175gr sierra, accuracy is at 2900fps in my rifle. 26" pacnor 1-9.5" match barrel. Sure did a good job on the bull I killed last year.

I tried 64.5gr of IMR 7828 with the 175gr GK and accuracy was good at 3/4" at 100 meters. Velocity was: 2820, 2807 and 2818.

This was with new W-W brass and Remington 9 1/2 primers, 3.300" OAL.

I loaded some more last night - up to 65.5gr - and I will post the results.

I was out yesterday and 65.5gr of IMR 7828 gave an average of 2850 fps, but groups opened up from 3/4" to 1 1/3". This is over book maximum, but was safe in my rifle. Please use caution when working up loads.

I was just gonna say, if you're getting .75" groups and 2800fps, what do you think another 100-150fps are gonna do for you? And the question begs to be asked: how did you determine the overload was "safe" in your rifle?

1. The rifle has shown to be capable of sub 1/2" groups with several loads, and 3/4" - 1" groups with many loads. It really is not out of the ordinary, so I wanted to fiddle with it some more. It's not the velocity that I chase. For example, I shoot 175gr Partitions at a decidedly pedestrian 2750fps. BUT, those loads give me almost unbelieveable accuracy.

2. There were no pressure signs and the velocity is within the range of what is quoted out of the Sierra manual:

62.8gr to 64.5gr giving 2800-2900fps.