Pressure of Surplus charge. strength. Laminated and other steel barrels lbs. lbs. lbs. are equal to a pressure of 6,022 1,700 4,329 Wire twist 5,019-1/2 1,700 3,319-1/2 New stub twist mixture 5,555 1,700 3,855 Old stub twist 4,818 1,700 3,118 Charcoal iron 4,526 1,700 2,826 Threepenny skelp iron 3,841 1,700 2,141 Damascus iron 3,292 1,700 1,592 Fancy twisted steel 3,134 1,700 1,434 Twopenny skelp iron 2,840 1,700 1,140 If the charge he increased to one ounce and a half, the length it occupies, and the lateral pressure by the jamming, will create an additional pressure in proportion, or near 2,550 pounds, as under:-- Pressure of Surplus 1-1/2 oz. shot. strength. Laminated and other steel barrels lbs. lbs. lbs. are equal to a pressure of 6,022 2,550 3,472 Wire twist barrel 5,019-1/2 2,550 2,469-1/2 New stub twist mixture 5,555 2,550 3,005 Old stub twist 4,818 2,550 2,268 Charcoal iron 4,526 2,550 1,976 Threepenny skelp iron 3,841 2,550 1,291 Damascus iron 3,292 2,550 742 Fancy twisted steel 3,134 2,550 584 Twopenny skelp iron 2,840 2,550 290 A charge of shot two ounces weight will be greater in pressure than barrels of these dimensions are equal to restrain, and, consequently, no barrels should be charged to this extent at any time; but inferior barrels, as a matter of certainty, are sure to give way if so loaded. Pressure of Surplus. 2 oz. shot. lbs. lbs. lbs. Laminated barrels, &c. 6,022 3,400 2,622 Wire twist barrels 5,029-1/2 3,400 1,619-1/2 New stub twist mixture 5,555 3,400 2,155 Old stub twist 4,818 3,400 1,418 Charcoal iron 4,526 3,400 1,126 Threepenny skelp iron 3,841 3,400 441 Damascus iron 3,292 3,400 Fancy steel barrels 3,134 3,400 Twopenny skelp iron 2,840 3,400