Armor-Piercing Cartridges

 

First experiments started in 1912 but it was not until 1917 that the first Armor-Piercing cartridge was adapted. One of the earlier experiments in 1917 was the AP bullet developed by Gardner. This bullet of 176 grain had a steel core which was covered by lead. The base of the bullet was marked: A.B.Co 17 

  

 

 

 

 

Experimental Gardner bullet                                                              Markings on base of bullet

 

The first official AP bullet was the model M1917. This bullet was developed by W. Clay of Frankford Arsenal. The bullet had a weight of 154 grain, a cupro-nickel jacket and an exposed lead tip.  

   

 

 

 

 

 

 Armor-Piercing cartridge model M1917. Headstamp: FA 18

 

In 1918 a new AP cartridge was adopted. This M1918 AP cartridge had 150 grain CN jacket and the exposed lead tip was removed. The bullet had a smooth cannelure about 0.1 Inch above the case-mouth. 

  

 

 

 

 

 

Armor-Piercing cartridge model M1918. Headstamp FA 18 

 

Further experiments were made during the closing year of WW1. One cartridge of the more unusual bullets had a blunt exposed steel nose. The jacket is CN and bullet weight was 149 grain. Further info is not available. 

 

 

 

 

 

 

 Experimental Armor-Piercing cartridge. Headstamp: FA 18

 

In 1921, after a few smaller experiments, a new bullet based on a design from W. Clay was standardised as the M1922 AP bullet. This was a 170 grain flat-based bullet containing a boat-tailed steel core. The bullet had a knurled cannelure to secure the core. This was the first time the black tip was used as identifier for an AP cartridge. 

 

 

 

 

  

 

Armor Piercing cartridge M1922. Headstamp: FA 34

 

In the thirties, a lot of experimenting was done with AP bullets. One of the more uncommen ones was a cartridge loaded with a bullet with a blunt steel nose. exposed. This was called the Tull Bryant bullet.

 

 

 

 

 

 

 

Experimental Armor-Piercing cartridge model: Tull S. Bryant. Headstamp: FA 32

 

 

 

 

 

Furthermore a series of tests with 2-diameter bullets, so-called High-Velocity Bullets were conducted. Most bullets have two driving bands and a reduced diamter in between. See picture on the left for two different variations.

  

 

 

 

 

 

 

 

 

 

 

Several experimental cartridges with High-Velocity bullets. Clearly visible is the forward driving band just above the case-mouth.

Headstamps: FA 33 & FA 34 

 

 

 

 

 

 

 

These tests resulted in the adoption of the Armor-Piercing M1 cartridge. The bullet used had a weight of 144 grain. Both bullet and steel core were boat-tailed. The cartridge had an extra cannelure below the case mouth to secure the bullet. 

 

 

 

 

 

 

 Armor-Piercing cartridge M1. Headstamp: FA 38.

 

A further development of the M1922 AP bullet led in 1939 to the introduction of the M2 AP Bullet.

Bullet weight was 168 grain and the core had a weight of 80 grain. With minor variations, this bullet remained the standard Armor-Piercing bullet for the 30-06 cartridge.

 

 

 

 

 

 

Armor-Piercing cartridge M2. Headstamp:

FA 40 , FA 40 , FA 42 , FA 54

 

 

 

 

 

 

 

Inside view of a M2 Armor-Piercing cartridge

 

 

 

M1922 and at a later stage M2 bullets were also loaded to specific velocities for testing armor plates. These so-called Plate-Testing cartridges can be identified by the silver over black bullet tip.

 

 

 

 

 

 

 Plate-Testing Armor-Piercing cartridge. Headstamp: FA 42   

  

In 1955 test were made with Ball and Armor-Piercing cartridges covered with a Teflon coating. The Teflon was applied to aid feeding and extracting to prevent cook-offs in machine guns. Although the headstamp on all cartridges is FA 54, box labels show that the loading was done in 1955.  

 

 

 

 

 

 

 Experimental M2 Armor-Piercing cartridge - Teflon coated. Headstamp: FA 54