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Derringeer · February 14, 2020, 03:59 PM

If the total length of the barrel is 4”, and it’s chambered in .40 cal loaded with a roundball, what’s the maximum charge suitable for the caliber regarding the length of the barrel? I read something about 25 grains of black gunpowder, more than that and it will only generate a bigger muzzle flash, but I believe the barrel was longer than 4” in that case.

If the barrel is short, can the velocity turn out higher with a smaller charge than a big charge, because with a smaller charge the ball will be chambered more deeply inside of the bore and therefore travelling a longer distance inside of the bore?

I’ll use Pyrodex P FFFG btw.

February 14, 2020, 03:59 PM	#3
Derringeer Member Join Date: December 21, 2019 Posts: 36	If the total length of the barrel is 4”, and it’s chambered in .40 cal loaded with a roundball, what’s the maximum charge suitable for the caliber regarding the length of the barrel? I read something about 25 grains of black gunpowder, more than that and it will only generate a bigger muzzle flash, but I believe the barrel was longer than 4” in that case. If the barrel is short, can the velocity turn out higher with a smaller charge than a big charge, because with a smaller charge the ball will be chambered more deeply inside of the bore and therefore travelling a longer distance inside of the bore? I’ll use Pyrodex P FFFG btw.