Original U.S. Cold War INERT M31 HEAT Anti-Armor Rifle Grenade Trainer - 66mm Crimean War The idea was unpopular

The idea was unpopular

The brim is surrounded in dyed black ostrich feathers

By the end of WWI just a year later

With the Ferdinand Mannlicher designed trigger guard / magazine housing assembly

the group (by then three flying squadrons strong) made its first aircraft transition -- from the P-12 to the Boeing P-26 Peashooter

Original U.S. Cold War INERT M31 HEAT Anti-Armor Rifle Grenade Trainer - 66mm Crimean War The idea was unpopularOriginal Item: Only One Available. Totally inert and demilitarized according to BATF guidelines with hollow body and deactivated propulsive charge. This rifle grenade round cannot be converted to an explosive device, it is just a trainer. Not Available For Export The M31 HEAT is a fin stabilized anti tank rifle grenade designed in the late 1950s to replace the Belgian ENERGA rifle grenade which was adopted by the US Army and US Marines as an emergency