The SLEM-1 (Self Loading Experimental Model 1) was a British semi-automatic battle rifle designed at the Royal Small Arms Factory at Enfield.
The Belgian design team had been working in Britain throughout the war, having escaped the occupation in 1940. They worked for the Small Arms Design Department which had been moved from Enfield to the Drill hall at Cheshunt, about five miles away. When the British General Staff decided in 1944 that the future British infantry cartridge would be the 7.92×57mm, the Belgian team designed the SLEM-1 (Self Loading Enfield Model 1).
When the 7.92×33mm Kurz was tested, everything changed and the British set up the Small Arms Calibre Panel that led to the .270 and .280 rounds. The Belgian team then redesigned the SLEM to become the prototype FAL, first in 7.92×33mm Kurz and then in .280. It was made in both normal and bullpup configurations. The extractor groove of the .280 was changed to meet U.S. specification and became the .280/30.
Post-war, the SLEM became the FN Model 1949.