There's data for that FTX bullet in a Trapdoor...
Manufacturer Powder Bullet Diam. C.O.L. Grs. Vel. (ft/s Pressure Grs. Vel. (ft/s) Pressure
IMR IMR 3031 .458" 2.590" 46.3 1,491 16,600 CUP 54.3 1,862 24,700 CUP
Grendel posted while I was fixing the columns.