Early in 1918 our Air Service field forces saw the need of a machine gun of larger caliber than the quick-firing weapons in general use. The flying service of the principal allies had developed an 11-millimeter machine gun for use in attacking the captive balloons of the enemy. This gun fired a projectile only slightly less than one-half inch in diameter. To meet this new demand our Ordnance Department found at the Colt factory about 1,000 Vickers machine guns which were being built on order for the former Russian Government. The department took over these guns and modified them to take 11-millimeter ammunition, and that step made it necessary for us to produce machine-gun cartridges for these new weapons.
We at once developed a modified French 11-millimeter tracer incendiary cartridge, which in later use proved to be highly satisfactory. In an experimental order the Frankford Arsenal turned out about 100,000 of these cartridges, while at the time the armistice was signed the Western Cartridge Co. was prepared to produce this class of ammunition on a large scale.
VIEW SHOWING SUCCESSIVE STAGES IN THE MANUFACTURE OF THE PRIMER BULLET AND CLIP FOR .30 CALIBER, MODEL OF 1906, AMMUNITION.
The top row shows the development of the primer cup and anvil. The second and third rows show the development in the manufacture of the cartridge case. The fourth and fifth rows show the development in the manufacture of the bullet jacket and the lead slug that fits into the jacket and finally the finished cartridge. The bottom row shows the development in the manufacture of the cartridge clip.
LEADING ENDS OF CARTRIDGE BELTS: BROWNING AT TOP, COLT IN CENTER, AND VICKERS AT BOTTOM.
In the belts, the bullets in black cases are loaded with tracer ammunition, those with black noses with incendiary ammunition, those having a ring just above the bullet casing with armor-piercing ammunition, while the rest are ordinary service cartridges.
Certain American concerns before April, 1917, had been producing 8-millimeter ammunition for the French government for use in its machine guns. When we entered the war our Ordnance Department found it necessary to continue the manufacture of these cartridges for the machine guns obtained from the French. Up to November 30, 1918, a total of 269,631,800 rounds had been produced under our supervision. These cartridges were manufactured by the Western Cartridge Co. and by the Remington Arms Co. at its Swanton plant.