The Hall rifle

[robinghewitt]

Got me a Harpers Ferry Hall in original 1826 flint

Everyone who photographs a Hall goes straight for the pop up breeching, so I thought I'd be different :thumbsup: :rotf:

 

[Tumblernotch]

The original microgroove rifling! And the first firearm to be fully interchangeable in its construction. Those Halls are a very unique weapon and John Hall was a genius and the real father of the machine tool trade. You should read about the troubles he had dealing with the superintendent of the Harpers Ferry Armory. Congratulations!
:hatsoff:

 

[robinghewitt]

It is most odd. The rifling starts quite some way down from the muzzle, you can't see it without a light, the breech end has a generous forcing cone.

I had heard that sinking the rifling below the muzzle was so you could muzzle load it, but in that case he would have crowned the rifling. The picture shows he didn't do that :hmm:

 

[Tumblernotch]

I've read the same thing. I suppose that since the ball was larger than the land diameter he figured that a soldier could ram the ball home once it dropped down the barrel a couple of inches. Gluckman, in his book says that the first 1-1/2 inches was reamed out smooth probably to facilitate muzzleloading. A lot of gunmakers never bothered to cone their muzzles, even on rifles firing tight balls. Most of the old rifles I've seen have no sign of coning at all and it looks like it would be very easy to cut or tear a patch on some of the muzzles. I personally prefer a slight cone since I usually shoot a pretty tight load.

The Hall was originally loaded by biting off the paper cartridge and pouring the powder in the breech and the ball was pressed on top of the powder. Sometimes the cartridge paper was used as a wad. I don't see the point myself. After 1830 they saturated the cartridges with nitre and they were simply loaded into the breech.

I suppose loading one of these from the muzzle would do in a pinch, but if the reason for this is because of excess fouling causing the breech to malfunction, I can only imagine what the 16 groove barrel would be like trying to drive what would amount to an oversize ball down it.

 

[Leonredbeard]

KR,
Think of it this way. Every time there is a quantum shift in a ubiquitous piece of machinary they seem always to allow for doing it the old way. Think motorcycles for instance: Electric start, yet with a kicker on it, in case the battery went dead. Same for cars, only decades earlier.
They didn't really think it through on those rifles, they just did it. They knew that in the thinking of the shooter, he always wanted an out if the new system failed.
volatpluvia

 

[arquebus]

Very nice Robin! I didn't realize the Hall was rifled like that. I've seen some European percussion target pistols with ultra-fine microgroove rifling, to the extent I couldn't easily count the number of grooves! I've sometimes heard it referred to as "cannon rifling". When it comes to guns, there is very little that is new.

 

[bingo1952]

I think the rifling was left square cut on the ends and not tapererd as in a normal crown so that it would have a cutting action similar to a broach rather than just displacing the metal.

 

[Zonie]

runnball: You may be right.
Assuming the soldiers had something to ram a bare ball into the rifled area of the bore, the sharp edges of the rifling would broach the grooves into the ball making loading somewhat easier.
The balls for these rifles were slightly oversize and were shot without patches so tearing of the patch wouldn't have been an issue.