barrel length & Max Velocity -Black powder

[TCAS]

How long of a barrel do you need to get maximum velocity from a 209 x45 or  209 x50 barrel.

I know we have many varibles such as Blackpowder, Pyrodex, 777, granular vs pellets, #11, 209, musket caps, etc...but... Would 30 inches be to long for max velocity???

Thanks

[RandyWakeman]

How long of a barrel do you need to get maximum velocity from a 209 x45 or  209 x50 barrel.

I know we have many varibles such as Blackpowder, Pyrodex, 777, granular vs pellets, #11, 209, musket caps, etc...but... Would 30 inches be to long for max velocity???

Thanks

Not the least of which is projectile weight and amount of propellant to be burned.

Thirty inches "would not be too long"-- though, the McMurchy tests showed minimal changes in velocity based on 100 grain loads in 22 vs. 26" barrels with 300 gr. sabots, and no difference in accuracy.