James - Proof from that angle is simple. The load referenced above is from Alliant, and listed as 2.5 Deq at 1090 fps. By dropping the powder charge to get into the black powder pressure range (or 7,000 psi arbitrary figure), by logic you will no longer achieve 2.5 Deq velocity.


"The price of good shotgunnery is constant practice" - Fred Kimble