Company introduced the Colt Ace pistol, a .22 long rifle caliber rimfire version of Colt's M1911A1 .45 ACP pistol for training purposes. This pistol was specific to the .22 rimfire cartridge, with a recoil equivalent to its cartridge. In 1933, Williams was contracted by Colt to redesign the Colt Ace with his floating chamber. The end result was the Colt Service Ace (“Firearm” published August 24, 1937), a .22 caliber rimfire pistol with a recoil stronger than that of the Colt Ace but less than that of its M1911A1 .45 ACP counterpart. In 1938, Colt introduced the Colt .22 - .45 Service Model Conversion Unit (Ace). Also designed by Williams, the conversion unit could be used to convert the 1911A1 .45 ACP pistol to .22 long rifle caliber rimfire for training. The kit allowed for the pistol to be converted back to its original 1911A1 .45 ACP. The kit was also used to convert the earlier Colt Ace pistol for use as a Colt Service Ace with the floating chamber. U.S. Ordnance Department After two years, he went to Washington, DC to show his work to the War Department. He received his first contract to modify the .30 caliber Browning machine gun using the floating chamber system to fire .22 caliber rimfire ammunition to facilitate inexpensive training. His conversions were permanent. Two patents were filed for this design on Mar 19, 1935, and published February 22, 1938: “Automatic Weapon Patent” and "Belt Feeding Means for Guns" . The original Williams design was redesigned and improved upon by others into a .22 caliber conversion unit that allowed the M1919A1 to be converted back and forth between .30 caliber and .22 caliber rimfire (“Automatic Firearm” published February 22, 1938). This conversion kit was designated the “Trainer, Machine Gun, Caliber .22 M3” (for the 1919A1). Subsequent versions were created for the 1919A4 (Caliber .22 M4) and AN-M2 (Caliber .22 M5 .30). Remington Arms Around 1937, Remington Arms contracted Williams to produce a .22 long rifle caliber rimfire semi-automatic rifle utilizing his floating chamber intended for the commercial market. The rifle designed and developed by Williams can be seen in two patents: “Firearm” and “Firearm” . The Williams design was not accepted by Remington. The rifle was redesigned by Remington employees K. Lowe and C.C. Loomis using the Williams floating chamber. The rifle was designated the Remington Model 550 and introduced in 1941. The