The BSA Autorifle was a British automatic rifle designed by Birmingham Small Arms Co. This rifle was manufactured by BSA under their licensing agreement with the Auto-Ordnance Corp. It was offered for British Army trials during the 1920s.
The weapon was an improved derivative of the Thompson Autorifle that could be operated manually if the two curved 'shutters' around the bolt head are moved into the down position, the mechanism is disconnected and the rifle can be used as a manual loader. This facility was a requirement in self-loaders offered for British trials at this period. The weapon took part in trials during 1927 against a Colt made Thompson, an 'improved' BSA Thompson, A gas operated BSA and the Farquhar Hill. Although in 1928 reports it narrowly beat the 'improved' BSA and the Farquhar Hill, It never advanced past prototype stages.
BSA Guns Ltd, a licensee of protecting the patents of the Thompson Autorifle made a handful of the 1923 model Thompsons as 'heavy rifles' with folding bipods and finned barrels. Surviving examples suggest there were Rifle and Light Machine Gun variants and 6 of both types were manufactured. The first examples were made in 1924 and an 'improved' variant in 1926. The 'improved' BSA Thompson had a shorter operation with a straight pull cocking handle installed at the rear of a cocking sleeve. One example survives today.
The BSA Autorifle is a delayed blowback operated rifle chambered in the .303 British round and fed from a removable 10 round box magazine. Much like its predecessor, it uses a bolt with 85° angled threads delayed by a 90° twist to unlock from a bronze nut until the gas pressure drops to a safe level to eject. The bolt cocks the striker on opening (a la Mauser) and fires from a closed position. When firing the trigger when pulled pushes a lever connected to a sear to fire the weapon. The receiver is of a round section with the safety switch at the rear along with the rear sight.
- Rifles of the World, Page 579
- BSA Autorifle at the Imperial War Museum