Reloading

Trying to work up some loads with this bullet but I'm not having much luck so far. Ive switched from 2400 to Vihtavuori N110 because it is much cleaner burning but i dont have a good reference for where i need to be with either powder in this cartridge with the 325 Swifts.

So far i have tried 24-26 grains with 10-12" groups at 50y and big velocity spreads (50-80 fps is common). At 26 grains it is still only going ~1450 fps out of a 10" barrel.

The bullet is .499 diameter and made for the 500S&W so im theorizing that it is not obturating and just skipping down the barrel. Increasing velocity/pressure SHOULD improve things but im not sure what the ceiling is and I definitely dont want to hit it.

Ive seen anecdotal evidence on the internet that the 350 Hornady XTP Mag and 325 Swift AF generate about the same pressure/velocity with similar charges but i cant find any info on the XTPs with 2400 or VN110 either.

Target would be something around 1550-1600 fps out of the 10" barrel.

thanks for the help. Matt