Comments on: Rifles and rifling http://www.brettschulte.net/CWBlog/2008/05/06/rifles-and-rifling/ Informed Amateurs Blog the American Civil War Wed, 08 Feb 2012 20:01:41 +0000 hourly 1 http://wordpress.org/?v= By: Craig http://www.brettschulte.net/CWBlog/2008/05/06/rifles-and-rifling/comment-page-1/#comment-542 Craig Wed, 07 May 2008 13:26:10 +0000 http://www.brettschulte.net/CWBlog/?p=850#comment-542 Personally I'm a bit more familiar with the rifling techniques used on the cannon of the ACW period. But the base technology is the same. One difference I'd point out, rifled muskets did not have, or don't seem to have had, as many issues with bore pressure as the rifled cannon. Hexagonal rifling, as seen with the British Whitworth cannon, just didn't play out well. The corners formed within the bore created stress points, weakening the overall gun. Also of note, Parrott rifles employed a gain-twist rifling, increasing in pitch from the seat to the bore. Hard to really gauge now days (what with pigeons nesting in the bore). I'd be interested if any of Parrott's notes regarding the choice of this technique exist. Personally I’m a bit more familiar with the rifling techniques used on the cannon of the ACW period. But the base technology is the same. One difference I’d point out, rifled muskets did not have, or don’t seem to have had, as many issues with bore pressure as the rifled cannon. Hexagonal rifling, as seen with the British Whitworth cannon, just didn’t play out well. The corners formed within the bore created stress points, weakening the overall gun.

Also of note, Parrott rifles employed a gain-twist rifling, increasing in pitch from the seat to the bore. Hard to really gauge now days (what with pigeons nesting in the bore). I’d be interested if any of Parrott’s notes regarding the choice of this technique exist.

]]> By: Fred Ray http://www.brettschulte.net/CWBlog/2008/05/06/rifles-and-rifling/comment-page-1/#comment-541 Fred Ray Wed, 07 May 2008 12:08:16 +0000 http://www.brettschulte.net/CWBlog/?p=850#comment-541 Surprised me too. The info comes from 19th C texts but has been confirmed by modern chronographs. Apparently the soft ball "upsets" when fired and does a better job of sealing than thought. Bilby goes into this in some detail. Surprised me too. The info comes from 19th C texts but has been confirmed by modern chronographs. Apparently the soft ball “upsets” when fired and does a better job of sealing than thought. Bilby goes into this in some detail.

]]> By: Drew W. http://www.brettschulte.net/CWBlog/2008/05/06/rifles-and-rifling/comment-page-1/#comment-536 Drew W. Wed, 07 May 2008 04:27:06 +0000 http://www.brettschulte.net/CWBlog/?p=850#comment-536 Fred, Coincidentally, I just started the Bilby book today. The whole comparative muzzle velocity data seems all over the place, and I must admit to not having seen quite the degree of disparity you mention, which is massive. Although current writers mention the higher muzzle velocity of the smoothbore musket, I recall coming across a chart from a firing test that determined that the rifled musket had a higher muzzle velocity than a smoothbore (but by a very slight margin...10-20 fps or something like that). I wish I could remember the source. I suppose you could look at the matter in different ways -- the rifle has more friction from the engagement of the skirt into the rifling grooves, but it also has the propellant gases "sealed" behind it; as opposed to the round musket ball which is loosely bouncing along the inside of the barrel. I am looking forward to Earl Hess's book about the rifled musket, to be published by UNC later in the year. Fred,
Coincidentally, I just started the Bilby book today.

The whole comparative muzzle velocity data seems all over the place, and I must admit to not having seen quite the degree of disparity you mention, which is massive. Although current writers mention the higher muzzle velocity of the smoothbore musket, I recall coming across a chart from a firing test that determined that the rifled musket had a higher muzzle velocity than a smoothbore (but by a very slight margin…10-20 fps or something like that). I wish I could remember the source.

I suppose you could look at the matter in different ways — the rifle has more friction from the engagement of the skirt into the rifling grooves, but it also has the propellant gases “sealed” behind it; as opposed to the round musket ball which is loosely bouncing along the inside of the barrel.

I am looking forward to Earl Hess’s book about the rifled musket, to be published by UNC later in the year.

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