HK51: The SAS' Full Auto Flashbang Dispenser
The HK51, a compact 7.62 NATO weapon, was developed by Bill Fleming for British SAS/SBS, not as an official H&K factory model. Originally designated MC51 by the British, it was later phased out for the HK53. In the US, Fleming converted HK91 rifles into full-auto HK51s, making them highly sought-after collector items due to their compact size and powerful caliber, despite a significant muzzle blast.









