Assuming a 200fps increase for barrel speed up...
Quickload shows this load on a 15” barrel as 2,888 for a charge of 45.5, and 82,068 psi. That is pretty close to what the results above are showing.
A proof load at 1.3 x SAAMI (78,000) would be 44.8-44.9, with velocity registering ~3,050 on a...