The Hodgdon loading guide for the 300 Blackout, 150 grn bullet, 16" barrel shows a max recommended load (20.5C grns) that only produces 33,500 PSI max pressure. This is compared with H110 at 52,800 PSI and IMR 4227 at 48,700 PSI. Despite this huge disparity in pressure, muzzle velocity of the...