Upsetting the base of the bullets experiment
The first real experiment was made with 4- inch barrel laid in V -rest; placing a box of snow , with the thin cardboard which formed one end, in front of and 24 inches from muzzle, the first shot was made January 15, 1902. The bullet printed in center of target, point on , making a clean half- inch hole and was recovered from snow completely flattened by the muzzle blast , thus ac counting for large print through the cardboard . It is hardly possible for those not present during these tests to appreciate the condition of affairs which are here indicated and recorded for the first time. Experiments were made with these short barrels, extending over a year, with different lengths, different combinations, with various alloyed bullets, with nitro powders both coarse and fine grained . Eighty- nine 187 -grain bullets were secured in the same shape as they left the different muzzles. It was noisy sport and necessitated stuffing cotton into one's ears for protection. This medley of tests was carried on at the range with concentric action and V - rest and multiplied out of curiosity. Perhaps the accompanying cut ( Fig. 32) will be of interest as it represents the 187-grain unshot Zischang bullets and a number fired from short barrels.
Figures 1 , 7 , and 14 are unshot bullets ; 2, 3, 4, 5 , and 6 are bullets fired from one short barrel into the muzzle of another, entering into and emerging from the .32-40 chamber of the second barrel. Figures 8, 9, 10 , 11 , 12 , and 13 were fired from a - inch .32-caliber barrel through a 3-inch .40-caliber which was firmly screwed to the former ; figures 15, 16 , 17 , and 18 were re markably upset with 21 grains sharpshooter powder, with no air space and .32–40 shell . All these bullets were loose- fitting or bore diameter. With figures 2 and 8 the charge was front ignited ; figures 6 and 13 were an alloy of 1 to 30, tin and lead ; figures 15, 16, and 18 were shot with 21 grains powder from a .32-40 shell , bullet entered half an inch into shell, leaving no air space, and extending .06 inch out of muzzle. The apparent tears seen in bullets were produced by a sharp steel prong, placed at varying distances from muzzle and also varying distances from line of low side of the rifle bore.
This prong was accurately adjusted by a screw and by it was determined at what position from muzzle many of these bullets commenced to upset , and at what position they completed their upsetting. It was found that many of them commenced to swell slightly at .06 inch from muzzle, and all that were tested received their full upset during first inch of flight of their bases from muzzle. Figures 15 , 16, and 18 pretty well illustrate W. E. Mann's putty-plug theory. Figure 17 was fired from a .62-inch barrel , .32-40 shell full of Du Pont's .30 -caliber high -pressure powder, leaving no air space, body of bullet extending .06 inch from muzzle and no prong interposed to obstruct. It will be noticed that lead bullets, figures 2 to 6, and even the 1 to 30, after being driven through a 3.12 inch , .32-caliber bore, were expanded into the .32-40 chamber, completely filling it . These bullets continued to enlarge as they passed into the larger portion of the still enlarging chamber until their diameter reached .386 inch for lead , and .379 for the 1 to 30, showing that they filled the chamber for two -thirds its length where its diameter is .388 inch ; all this with a normal charge behind a loose fitting bullet . It will also be observed that front ignition, as in figures 2 and 8 , does not do away with upset , as has generally been supposed by some well-known rifle men. Shots represented by figures 8 to 13 inclusive, being bore diameter, not only upset into the .32-caliber rifling, but after traveling 3.12 inches they again upset and, with the lead bullets , completely filled a .40 - caliber to bottom and corners of the grooves. The putty -plug theory is here again confirmed, but does not encourage the theory that bullets must be larger than bore in order to take its grooves. Before snow-shooting and oblique -base experiments were made, or short barrel tests attempted, brother William claimed that a lead bullet in a rifle bore was like shooting a plug of putty from a popgun. A little later, while working on the range, this idea was again brought up when he asserted , still more emphatically, and seemed to show how soft bullets would stick in the bore, being pushed out sidewise, either side first as might happen , by powder blast behind , like pushing a plug of putty from a popgun, and it was decided to thoroughly test the matter. Measurements taken from bullet bases which were recovered during snow shooting experiments, seemed to bear out W. E. Mann's theory , and short barrel tests showed up his theory so thoroughly that they were multiplied until it was substantiated .