I've only used RE-15, N140 and Varget with the 75 grain A-Max in my 223 Ackley. The newest Hornady manual shows a starting load of 748 at 20.2 grains and the max being 24.0 grains. This data is for a semi-auto service rifle. Hornady doesn't show 75 grain A-Max data in the bolt gun, their data is with a 1 in 12 barrel so stops at the 60 grain V-Max. I would think the max load in a bolt action would be about one grain higher. Of course, only actual load development will show what is maximum in your rifle.