I am telling the truth about the velocity I get from using N570 powder.
We have shot over 2 chronys, and they bot said 909 m/sek.
The same powder, 97grs behind a 250 grs Scenar, came out at 990 m/sek (3248 fps).
I put all my data into Shooter, and shot that bullet out to 1300 meters, dead on. I don't have a calibrated chronograph, but I think it is pretty close.
I have now bought some Norma brass, and have 90 grs of N570 behind the 300 grs SMK. Will shoot tomorrow, and see what I get. Hope to be in the 860 m/sek area, then maybe caselife is longer, and also barrel life. The barrel cost me 1350 USD, so I hope it will last a while ;)
Good luck with your project. I know it will be a killer ;)
100 meters, 5 shot group.
300 meters, 5 shot group
600 meters, 5 shot group, could have been better, but it was windy.