Page:Popular Science Monthly Volume 92.djvu/556

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��Popular Science Monthly

��two stoppages due to imperfect ammuni- tion, one cartridge failing to feed in, the other refusing to fire. Consider that this means twenty thousand terrific shocks to the operating mechanism, twenty thou- sand vicious drives baclcward of the mechanism when the powder pressure of fifty, thousand pounds per square inch rose in the chamber for each shot. So fast does the mechanism of such a gun work that the eye cannot follow the mov- ing parts. Imagine a single-cylinder au- tomobile engine being asked to work twenty thousand times so quickly that the eye can't follow the piston in and out, and started from inertia to top speed in probably one-fiftieth second.

Compare this with the following official record of the Benet-Mercier at Texas City, in August of 1914, the comparative machine-gun trials between the Benet — the then standard type in our army — and the light Vickers rifle:

"It was found during these tests that it was practically impossible to obtain a continuous fire of 1000 shots from any of the Automatic Ma- chine Rifles, M 1909 (The Benet-Mercier). During two of the tests such fire was required, but owing to severe and frequent jams of various kinds, some of which could not be corrected with- in a reasonable time even by a skilled mechanic on duty with the board, it was necessary to dis- continue this particular kind of test in so far as this type of gun was con- cerned."

Also, said the board, regarding the belt-feed Vickers— the same type as the Browning in feed details:

"The greater numl>er of cartridges in container — 250 — • resulted in a more continu- ous, concentrated fire from the gun. While the rale of fire of the Vickers gun is slower than that of the service machine rifle — IJcnet — the actual number of rounds fired when both tyjtcs of gun were working satis- factorily was in the |)ropor- tion of 10 to in favor of the Vickers, due to loss of time in insert ing the shorter feed strips of the IJenet automatic macliine ride."

Against this Benet record of not one thou- sand rounds continuous fire, the Vickers guns —

��four of them — were fired more than sixteen thousand times — six thousand rounds from one of them without "a malfunction that could not be easily and quickly corrected by the gun crew."

This resulted in the adoption of the Vickers gun — and now comes the great Browning machine gun of much the same type — belt feed and water cooled — that was fired twenty thousand rounds with but two stoppages, both due to ammuni- tion. The fine Vickers has to take second place.

After the adoption of this splendid new Browning, the Board asked Browning to design one on the same lines but air- cooled for airplane use. Air is efficient for an airplane gun because the rapid motion through the air cools the gun surface, where this is not true on the land. This has been done, and the gun adopted for airplane use. Water cooling is not, of course, practical for airplanes.

Browning's Airplane Gun

Browning filled the order with a fifteen- pound automatic rifle or machine gun, as it really is, gas-operated like his old Colt, and air-cooled. It is fed by a twenty-shot magazine, and, with its very light weight and small magazine, it is as much a true automatic infantry shoulder rifle as it is a

���This Is Browning's Colt Automatic Machine Gun I.ilce ;ill ;iir-c<.oli-(l inacliine kuiis. lln' Colt li;is ils faults. If you iuail- virlcritly leave a cattriarrcl afti-i I'lrlnn a ninnlu-r of romuls. the heat of tin- (jini will cause tli«- cartridge to lire ilselt in alK)Ut four secotKlH. ifKanlle-s of all the safety devlees provided. And yet tlic Colt is one of the most ellieienl air-cooled nuns made. It is operated l>y I lie pressure of the powder Rases. The rate of lire is about four hundred sliola a minute. Tlic cartridKes arc fed lo the gun hy a belt containing two hundred and fifty shots of regulation ammunition

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