153,311 of this model revolver were purchased by the U.S. government between April 6, 1917 and December 1918 for use during WWI. This was an expedient measure due to lack of M1911 Automatic Pistols.
Originally designed in 1917 by John Browning, the B.A.R met a need for a relatively light automatic squad support weapon. It was used from 1918 through the Viet Nam War.