Japanese Type 89 "Knee Mortar" 1929 - 1945:

New to me - I recently saw one of these on the TV series "Pawn Stars" .. These "Knee Mortars" were very versatile and effective weapons that were a blend of a grenade launcher/mortar that reached out into the range of 120 - 670 meters. They caused much damage to US Forces in the Pacific WWII.

Although quiet light weight and looking much like a simple tube launcher - they were sophisticated & adjustable for range and could be very accurate - having a rifled barrel.

What they were NOT was .... NOT FIRED BRACED ON THE KNEE OR LEG !

Trigger fired at an angle of 45 degrees - the range was adjustable using a scale and the grenades are an efficient - clever design .. for example they slide freely into the barrel when loading - but have a driving band that expands and engages the rifling when fired.

As is often the case, FORGOTTEN WEAPONS.com explains this system better than I might: Link to their video:

https://www.forgottenweapons.com/type-89-knee-mortar-at-james-d-julia/

TYPE 89 Mortar Shell - Grenade

-Brass Driving Band at Base.

Marty K.