51mm Light Mortar
The 51mm mortar is a tube used for giving trainees something to carry and occasionally for getting rid of old 2 inch ammo, leading to spectacular innacuracy. When placed against a tree and used in the direct fire role, the 51mm is a thing to behold.
Emperor Mong's advice: When you see yourself surrounded, you can always prime the bomb and use it as a big feck off grenade. Depends on the kind and country of origin there are always way to prime them. Hilarity ensues along with a bit of hearing loss, permanently (which is a good thing anyway since you don't have to listen to the nagging by the missus no more)