This GPMG was developed after Britain's adoption of the NATO-standardized 7.62×51mm cartridge. It was a belt-fed conversion of the Bren, designed chiefly by Josef Veselý, a Czech engineer. When the British Army arranged GPMG trials in 1957, BSA submitted this gun for testing and it was designated the X16 by the Army. It competed against the FN MAG, the AA-52, the M60, the Madsen-Saetter and the SIG MG710, and was considered one of the highest quality contenders. However, it was also very expensive to produce, and this factored into the Army's decision to reject it and opt for the FN MAG instead. There were no attempts to market the BSA GPMG abroad.
The BSA GPMG's belt feed was operated by a gas piston, and gave very few stoppages.