Velocity and Range Ot Guns from the Black-Powder Muzzle-Loader to the Smokeless-Powder Rifle
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360 SCIENTIFIC AMERICAN April 20, 1918 Velocity and Range ot Guns From the Black-Powder Muzzle-Loader to the Smokeless-Powder Rifle By J. Bernard Walker THE energy of projectiles varies as their weights and or even two subsidiary flashes, suggesting a belated at the same instant. The fire-surfaces at this moment the sq uares of their velocities. If we dOL.ble the firing of the powder pockets. are comparatively small, and the pressure is corre weight, le!l.ving the velocity the same, we secure twice spondingly low; but as the burning proceeds in a radial Lyman Tries Slow-Burning Powder the energy in the projectile; but if we double the velocity, direction, the holes in the powder-cake become constantly leaving the weight the same, we secure four times the BlIt Lyman was on the right tralk. He determined to enl'l.rged and the fire-area continuously increases, 9S energy. Hence, the gunmaker, in his tireless endeavor use the whole charge in one enlarged powder chamber, also does the pressure upon the projectile, and the to increase the inertia of the pro power of artillery, 1 jectile is gradually has sought to in and slowly over crease velocity to come. After the the maximum de projectile h'l.s been gree compatible with started from its the various condi seat, and as it passes tions imposed upon through the gun, him by the problem. the pressure exerted upon it is substan An Early High tially maintained by Velocity Gun reason of the con One of the earliest tinuously extending attempts to secure fire area, and this very high muzzle continues until the velocity was that powder-cake is sub of A. S. Lyman of stanti'l.lly all con New York, the in sumed; it being the ventor of the Lyman design to construct Sight, which was Fig. 1. The Lyman-Haskell, multi-charge gun of 1880 the cartridge so that widely used on the the powder will be sporting riflcs of his day. Somewhere about the year and make a powder that would burn progressively. His all consumed before the projectile reaches the end of the 1880, Lyman devised what he called an "accelerating progress is revealed in a patent (No. 321,374) iSSued bore. In this way a comparatively low maximum gun," in which he aimed to secure a great increase in to him June 30th, 1885, the drawings of which are re pressure may be substantially maintained upon the penetration and range by an unprecedented increase in produced herewith. The powder formed a cylindrical projectile for the greater part or the whole of the time the muzzle velocity. He built a 2Y2-inch gun which, cartridge, and was to be "hard and dense, so that the it is passing through the barrel of the gun, the effect \lihen tried out against � 5-inch Whitworth gun, is said fire cannot penetrate into it, but must burn only on its being to relieve the walls of the gun from dangerous to have shown, at short ranges, a greater strains, and to give the projectile a greater penetration. velocity and more effective power than Then Col. J. H. Haskell became as is aC(;Qmplished by cartridges of common sociated with Lyman, and a new gun COQstruction. " of the same geneul design was built in It should be stated here that the per 1881, and w'ts given a lengthy series of forated grain was first introduced by that tests which attr!l.cted much attention. The great artillerist, General Rodman, during SCIENTIFIC AMERICAN sent representatives the period of the Civil War. to the trials, and published a sketch, made Super-Range Awaited Gun Steel and by its artist at the proving grounds, which Smokeless Powder is reproduced on thi3 page. This gun was of six-inch bore and Thus we see that over thirty years ago measured 25 feet in length; that is to say, this American inventor, with his slow it had the amazing length, for those days, burning powder, large powder chamber, of 50 calibers-a caliber-length which is and 50-caliber gun, had combined those not surpassed by the high_velocity guns of principles of ballistics which only awaited the present day. Further particulars of improvement in gun steel and the develop the Lyman-Haskell gun will be found in ment of smokeless powder to make a the current issue of the SUPPLEMENT. 750mile r'l.nge possible. These principles are clearly illustrated in the drawing, Gun with Five Powder Chambers Fig. 5, comparing the powder pressure It was well understood that to secure curves of an old 12-inch, black-powder, great penetration and range, high velocity breech-loading gun with a modern 12-inch, was necessary and that high velocity Fig. 2. Perforated cylindrical-grain powder of 1885 smokeless-powder rifle. The black powder, called for a large powder charge and high rapidly consumed, gives a chamber pres powder pressure. But the gunmakers of that df..Y did surfaces" and it was to be perforated by holes running sure of 24 tons to the inch, which falls rapidly to about not possess the superior gun steel that is available through it longitudinally from end to end. Y2 ton at the muzzle; the smokeless powder, more slowly today, and hence it was necessary to keep the powder Said the patent: "To fire the cartridge, a flame is consumed, rises to 16 tons at the chamber and falls pressure within limits. In other words, Lyman and forced down the firing-tube and ignites the front end of the gradually to 6 tons at the muzzle. Haskell realized that in order to secure high velocity powder-cB.ke and fla.shes back down the perforatiC'ns in The Super-Range Gun with low powder-pressure they must find a way to burn the powder-cake, igniting the surfaces of all the holes a large powder charge progressively. Coming now to th.e question of what kind of gun it So they decided to build a very long gun and provide it is that the Germans are using to throw shells 75 miles with five separate powder chambers, one at the breech and into Paris, three different types have been suggested: the other four progressively along the gun and below it. 1. A gun using a compound shell; The shell weighed 150 pounds (a modern six-inch shell 2. A gun using a sub-caliber shell; weighs 100 pounds) and the powder charge was 130 3. A gun of standard type but with a large powder pounds. The small charge of powder at the breech chamber and a very long barrel. served to start the shell, and. it was believed The Compound Shell that as the latter passed down the bore, • pit uncovering the other four powder chambers, i The proposal to use a compound shell ' ...... their contents would be successively 1 ' ........ has been made frequently during the past ignited, and that their combined action I ; "" ... few years. The study of the problem, ... -... ---- ......... J . t', would serve to maintain a high average ,. shown herewith, was sent to this office by . IP '-'- ' "- pressure on the base of the shell until it : .... ,.. f , W. Thibaudeau, Member of the Canadian left the muzzle. I ',- : \ Society of Civil Engineers, of Montreal. ..... -.---.. - : \ : \ -.. ' The powder charges, velocities, etc., are of Theory Right-Practice Wrong -_ \ \' 1' ' I course assumed; and the object of the , , \, \ The theory was correct; but it did not 1.. \ drawing is to show how' the problem would work out in this particular application I \ have to be worked out. The projectile \ : \ \ as will be seen from the fact that, in spite consists of three rifled shells and a Q q' qllt' of the huge powder charge, the highest final loaded explosive shell. The com muzzle velocity obtained was only 1,700 pound projectile, fired from 0, itself suc Fig� 3. Theoretical study of suggested compound shell and its trajectory feet per second. Just what was the cessively discharges a compound pro- Assumed charge A gives velocity to B. C. D of 1600 footrsecond8: charge B gives velocity pI trouble our article written at the time does to C. D of 1500 f. s.; charge C gives D velocity of 1400 f. s. Assumed muzzle velocity at 0= . jectile !l.t the points P and of the tra not state, further than to say that it was 3000 f. s. and velocity at p. pi, pt. before explosion of charges A, B. C = 2400 f. s. Assumed jectory, the final projectile D being dis surmised that the successive charges did new velocity acquired by explosion of charge A at P= � velocity acquired by explosion A + charged at p2 and continuing the tra 2400 = 3200 f. s.; at pi � velocity acquired by explosion of charge B + 2400= 3150 f. s.; at pt not fire with regularity. An eyewitness jectory to R3. � velocity acquired by explosion of 'charge C ± 2400= 3100 f. s. Trajectory of compound tells us that, instantly following the first shell = O. P, PI, pt. pI. R', and its range is 0 RI. Trajectory of single shell=O. p. R. and its Supposing that such a projectile could flash of the gun, there w01lld often be one raolge is 0, R. be made to function, its inaccuracy would © 1918 SCIENTIFIC AMERICAN, INC · April 20, 1918 SCIENTIFIC' AMERICAN 361 be S(> great as to render the gun useless, even for hitting 1. By the use of a; sub-caliber shell; such a big target as Paris, and this for the following 2.