I wouldn't be surprised if a new powder was developed for the 50 BMG. But Browning wasn't restricted to commercial powders, and would have had Dupont engineers doing the actual chemistry while he just tested the ammo & his new gun for the U.S. goverment. Back when it was designed the 50 BMG was considered an anti-tank gun and could penetrate the armor of many of the WWI tanks. As tank design advances quickly left the 50 BMG ineffective, its mission was changed to attack trucks, buildings and aircraft; which it still does very effectively.