Development started in 1951 for use in the SCHV or Small Caliber High Velocity programme conducted at Aberdeen Proving Ground. The first specimen used a 30 Carbine case loaded with a commercial bullet. The second specimen used a modified 222 Remington case. It was the loading by Olin with the thicker 0.022” GM envelope. The third specimen was the final loading by Frankfort Arsenal for recoil impulse tests and was loaded with a 36gr. soft nose bullet.

   WCC 54 Box