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Cost of an Ancient Warship
"Keith Willshaw" wrote in message ... "vincent Brannigan" wrote in message ... Keith Willshaw wrote: The napoleon was a smoothbore and its production involved much less boring and turning than a rifle The true comparison is between an iron smoothbore and a napoleon. The columbiads while admittedly larger than the napoleons were also smoothbores I agree that rifling adds to cost, but not that much. I rather disagree. The cost of boring (drill the main center tube) and turnign (trunnions) is the same. However the machinery required to cut rifling in a cannon bore is of an entirely different order from the simple boring process adopted for a smoothbore. There's a good reason why rifled cannon didnt appear on the battlefield before the 1850's and the rise of the machine tool is a large part of it. It wasnt until 1841 that the first standardised screw threads were introduced by Whitworth for example. I'll chime in here being a Gun enthuist as well as knowing a thing or two about the rifling process. to rifle the barrel is actually a 3 step process, Bore, Ream and rifle. you start with a single point rifle drill to drill the basic hole this is the most dificult part drilling a stright hole. then you ream it easist part to the finished Lands demension. Then you rifle. The rifling process takes about 4-5x the amount of time to Bore or ream. The rifle cutter will cut one grove per pass it then indexs and cuts another and it cuts a very little bit of metal. ( in 0.00001") per pass. so to rifle a barrel takes literally thousounds of repeated passes. Even on a fully automated machine it takes a long time. Jim |
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