I'll second the idea of using 243 and 260 data. It isn't too hard to fall in the middle of two sets of data. That, and use a chronograph to see when you're getting pretty close to max velocity. All I've ever used are 100 Hornady Spire Points in the 25 Souper with IMR 4350. That'll change soon as I'm moving all 4350 loads to the Hodgdon version of 4350 as soon as current supplies are used. I was also thinking of trying Ramshot's Big Game and loading a series of rounds until I get back to the velocity currently obtained with IMR 4350.
