The gammon bomb is a kind of homemade grenade typically SAS borderline artisanal
they were prepared in the regiment and not in the factory at the beginning
In his book Special Air Service, Lieutenant Edgard Thomé of the 3rd RCP (French SAS) describes it as follows:
I almost forgot the main thing:the Gammon bombs. It's a derisory-looking device, a kind of little black bag in elastic jersey that could almost be confused with those crosshairs with which women encumber themselves when they go to parties. But it's a crosshair inside which you won't find compacts, powder puffs or cleaning accessories. Stuffed with two or three pounds of high-explosive plastic, no tank tracks and virtually no armor survived its impact. You can also mix thermite with plastic, and the enemy tank will then burn without forgiveness.
Originally, the Gammon were only intended to destroy armored vehicles. Later, when we get to know the Nazis better, when we discover the tortured bodies of our murdered comrades, we too will become wicked. We will care less about taking prisoners than about killing without remorse.
The Gammon will then become infernal machines, riddled with bicycle chains, colt bullets or bolts. We will use it indifferently against tanks or infantry. They chop or tear everything within a radius of twenty meters:express packages for hell, they lay their victims down by dozens at a time. Moreover, their explosion is quite similar to that of a mortar shell and I have always seen the Germans mistake this and imagine at the same time that they were attacked by heavily armed forces whereas it was a handful of us.