540 



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 tliis 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 cattri<lKo in Hie l>arrcl 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 tlie 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 



