Originally Posted by Scrubbit
Montana, I'm getting about 2875 fps when the outdoor temp is around 55 deg with a 26 in barrel and H4831 SC. Get about 2810 when it's about 0 ambient. How does that compare to Retumbo and H1000?
Broz uses H1000 in his 28" 300 WM and is getting about 3050 fps with the 215's which is about a 50 fps increase in velocity over the 210 VLD's. The 2 advantages of the 215's over the 210's is shorter bearing surface and higher BC. The shorter bearing surface will get you more velocity. Overall, the 215's will give you over 100 m more effective range.
The slower powders like H1000 and Retumbo do better in the higher volume to bore cartridges and longer barrels, especially with heavier bullets. Chances are you will see more velocity from H1000 than H4831sc and more velocity from Retumbo than H1000.
Running your MV, BC and elevation, I am showing you a little shy of 1800 fps @ 788 m