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Originally Posted by archer
Great project loving the whole thing. Richard is right as well, we need to try getting a safe competition started for comparison. Elgood mentions Akbar proofing his Toradors by filing the barrels to the top and that half full barrels had a tendency to burst.It must have a reference to chamber not the barrel? I have always read that with black powder you must have a bullet seated directly on top of it to avoid air space and excessive pressures. Steve
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Air space in a chamber or barrel can created dangerous pressures no matter what the breech configuration or powder requirements of a firearm are. I've had a lot of experience handloading cartridges using black and nitro powders for various vintage firearms, and the one thing the manuals emphasize is never to under-fill a cartridge case for this very reason. Light "squib" loads require a filler like kapok fiber (some shooters used wadded up toilet paper!) between the powder and the seated bullet. Also, firearms safety experts always warn never to shoot a gun whose barrel has an obstruction of any kind, whether a bit of mud, a forgotten cleaning patch, or whatever.
I agree regarding the Akbar text, it's hard to believe that "filling to the top" meant to the muzzle. As a matter of comparison, here is a description of proof firing as done in Spain in the 16th cent., this from a 1644 treatise by gun expert Alonzo Martínez de Espinar in his
Arte de Ballestería y Montería :
"...to make sure of its solidity and resistance, it was tested by pouring in a quantity of powder equal to the weight of the ball that it took, with a tight-fitting tarred wad; on this the weight of four balls of large shot with another wad like the first; when the barrel was charged in this manner, they fired it off in a remote spot, and it it stood the same test three times, they put the marks on it and continued their work to its completion."
Considering the relative density of gunpowder and lead, the powder charges in these proof loads must have been considerable.
The rigorous testing was apparently continued in following centuries in that country, and enabled such qualitative improvements in barrel-forging technology that by the 18th cent. Spanish smiths, using the very ductile iron recycled from Vizcayan horseshoes, were able to produce shotgun barrels that of such lightness and strength that they were widely faked in Germany and elsewhere, and which equalled if not superseded the tubes made by the legendary Cominazzo family of Brescia in the previous century.