Originally Posted by HockaLouis
I know it can be done -- Daniel Day-Lewis did it in Last of the Mohicans!
Seriously, it was a common emergency practice to dump your powder down the 'bess, drop a loose ball, smack the gun butt-down into the ground where some of the powder trickled into the pan through the enlarged vent-hole and you fire after seconds!
I think I read somewhere that the really good british soldier could fire 3 rounds a minute using this method. They used a premeasured paper cartridge though. The cartridge had perforated line around the powder end with a paper "tail" that protruded from it. The soldier took the cartridge from his pouch grasped the tail in his teeth and tore the end of the cartridge off, poured a little in the priming pan, closed the frizzen, poured the rest down the barrel followed by the ball slammed the butt of the musket on the ground a time or two, cocked and fired. This was a smooth bore " brown bess" musket, not a rifle.
As for the Last of the Mohicans (great movie, way better book, read it). I suppose that with a lot of practice you could "time" a pour of powder directly from your horn into the rifle and be somewhat sure how much powder you poured in but I think accuracy would be erratic with that method. I think most of the people carried a measure attached to thier horn, it would only take an extra 4 or 5 seconds to pour into a measure then into the barrel and the resulting precision would be well worth it.
I am by no means an expert on this but I know that unmesured powder charges can sometimes cause bad things to happen.