I've got some pressure tested data from Dupont for the 7X57. Using IMR 4227, which is alot slower than Blue Dot, they recommend 22.5 grs. for 2080 fps. with the 130 gr. Speer. With the same charge, and the 160 gr. Speer, they get 1890 fps. Pressures run from 44,300 CUP to 46000 CUP. These are their maximum recommended loads.
I have to conclude that using up to 24 grs. of a much faster powder, and getting alot more velocity is being done at alot more pressure. Sure doesn't give me the warm fuzzies.
One thing guys like Norman E Johnson have pointed out when using greatly reduced charges is the use of magnum rifle primers instead of standard primers. That improves accuracy a great deal. E
