UPPER ROW—.30 CALIBER RIFLE CARTRIDGES WITH BULLETS FROM LEFT TO RIGHT, AS FOLLOWS: ARMOR PIERCING, TRACER, INCENDIARY, ORDINARY.

LOWER ROW—.45 CALIBER AMMUNITION IN CLIP FOR REVOLVER—.45 CALIBER AMMUNITION FOR PISTOL.

Equally interesting was the construction of the armor-piercing bullet. Heavy and solid as the jacketed lead bullet used in our service guns seems to be, when fired against even light armor plate it leaves only a small mark upon its objective. As soon as the cupronickel jacket strikes the armor plate it splits and the lead core flattens out and flies into fragments. The armor plate may not even be dented by this impact. Yet change the core of this missile from lead to hardened steel and an entirely different result is produced. Our armor-piercing bullet was made with a cupronickel jacket for the sake of the gun barrel. The inner side of this jacket was lined with a thin coat of lead which was made thicker in the nose of the bullet. Finally a core of specially heat-treated steel completed the construction of the projectile. When this missile is fired against armor plate the jacket splits and the lead lining virtually disappears from the impact, but the pointed steel core keeps on and bores a hole through the plate as it might through soft wood.

The production figures show the degree of success which we attained in the manufacture of this special ammunition. Up to November 30, 1918, the E. I. du Pont de Nemours Co. had produced 6,057,000 tracer cartridges of .30 caliber and 1,560,000 incendiary cartridges of the same size. The Frankford Arsenal turned out 22,245,000 tracer cartridges of this size, 14,148,000 incendiary cartridges, and 4,746,900 armor-piercing cartridges. We placed an additional order for armor-piercing projectiles with the Dominion arsenals, which delivered to us 1,980,000 of such cartridges.

We also set out to develop new manufacturing facilities for the production of this special aircraft ammunition. Excellent tracer bullets were produced by the National Fireworks Co., of West Hanover, Mass., and that company was getting into a satisfactory production stride when the armistice was signed. The Hero Manufacturing Co., of Philadelphia, Pa., also was turning out an approved incendiary bullet when peace came. These various special bullets were loaded in cartridges at the Frankford Arsenal.

When the fighting ceased we were working on the development of armor-piercing bullets that would also be incendiary; and armor-piercing bullets that would also contain a tracing mixture. It was thought that bullets of these types would be particularly valuable for aircraft use. While we had done considerable experimenting along both lines, no satisfactory types had yet been developed.

There was another class of small arms for which we also had to produce ammunition on a war scale. Our automatic pistols and revolvers demanded .45-caliber ball cartridges. In normal times the Frankford Arsenal had been almost our sole producer of these cartridges, and it had attained an annual output of approximately 10,000,000 rounds of them. This quantity was nowhere nearly adequate for our war needs, especially after the decision to equip our troops much more numerously with pistols and revolvers than had formerly been the case.

Consequently it was necessary for us to develop additional manufacturing facilities for .45-caliber ammunition. We did this by placing orders with some of the same manufacturers who were developing the .30-caliber production. Because it was necessary for us to give preference always to the rifle and machine-gun ammunition, the manufacture of pistol cartridges was not carried through as rapidly as some other phases of the ammunition program. However, a satisfactory output was reached in time to meet the immediate demands of our forces in the field, and this production was expanding and keeping ahead of the increased needs for this sort of cartridges. The total war production of .45-caliber ammunition by the various factories was as follows:

United States Cartridge Co.75,500,000
Winchester Repeating Arms Co.46,446,800
Remington Arms-Union Metallic Cartridge Co.144,825,700
Peters Cartridge Co.55,521,000
Frankford Arsenal12,349,200