RE: T-7 vs. APP measurements
Zrider, I shoot the same CVA .45 Magbolt, and I use 95 grains FFFG 777. 1.5" groups at 100 yards with (take your pick) .40 cal 200 grain XTP, 200 grain SST or .357 195 grain Dead Center. Last couple seasons I used 80 grains 777. Play around and see what shoots best with your rifle, but I wouldn't be afraid of going up to 100 grains FFFG 777.
On the other hand, if you're planning on staying with the 225 grain Powerbelt, I'd keep the charge to 80 grains max. - many others have proven that if you push PB's too fast, you get less than ideal results.