"Carbine Williams", aka David Marshall Williams, has a reputation as the designer of the M1 Carbine, and a very colorful history. He was a moonshiner who pled guilty to second degree murder of a sheriff's deputy and served time in prison. He gained a reputation as a gunsmith in prison, fixing the department's guns in the prison shop, and was eventually allowed to work on his own firearms designs. Eventually released, he patented a design for a gas tappet system. The system was used for the M1 Carbine (that was really the extent of his contribution to that design) and a related "floating chamber" system was used in a .22 rimfire conversion of the 1911 pistol and the M1919 Browning machine gun.

The Colt Service Model Ace used William's floating chamber concept to improve their previous Colt Ace .22 1911 conversion. The first prototypes were ready in 1932, and production ran from 1935 until 1945 (plus a reintroduction from 1978-1982). Most sales went to the US military, which bought 13,808 complete pistols and a bit more than 2,000 conversion kits. They were used for marksmanship training, as .22 rimfire ranges could be built in many more places than ones safe for full-power .45 ACP.