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Old 25th December 2011, 08:54 PM   #35
cannonmn
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Join Date: Jun 2006
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Jim, I'm not trying to pose as an expert in any sense, but looking at your question regarding recoil, I'd say the relative compaction of the powder isn't a major parameter in the recoil calculation, but certainly contributes to it in the form of whatever muzzle velocity the projectile obtains. If we are to believe the tests which have been done in recent years by very knowlegeable museum staff and others, there wasn't much difference in the muzzle velocities achieved by 16th. C. handgonnes and say smoothbore muskets of the 18th C., something like 450-550 m/s if memory serves.

Recoil is the result of the mass of the projectile and the velocity it obtains in the gun (m x v = momentum,) and is equal to the momentum of the projectile because that action has an equal and opposite reaction. The gonne is propelled rearward initially by the same momentum as the moving projectile has at the muzzle, but reduced by the mass of the whole gonne, which in those days was considerable (many were easily 50 pounds.) This resulted, I'm guessing, in a modest recoil since the relatively very heavy gonne starts rearward at a very low velocity compared to that of the projectile. The common belief is that the hook on the front of an arquebus or hackbut is necessary to convey the severe recoil to a solid wall or tripod, but I've always wondered about that. Perhaps if a gonner had to shoot the piece all day long in a siege situation, even a modest recoil would beat him up too much, thus the hook requirement.

Some of the early hand-cannons that had relatively large bores, and short, light barrels, with only an iron tiller to hold it may have been very hard on the shooter. If we assume that muzzle velocity didn't vary too greatly, then the ratio of projectile weight to total gonne weight would give a good indication of relative recoil.
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