with black powder/bp substitutes being a total explosive it should burn everything you put in it.
Yes, and no. BP is an explosive, but it's blast characteristics are much different than smokeless powder, and thus the pressures generated are considerably different.
take your ml and shorten the barrel 5-6in ,i bet it will shoot faster. only thing slowing the bullet down is friction,less time in the barrel,less friction. short barrel shoots faster.
with smokelss it would lose speed.
