“The safety pin of hand grenades would be pulled and the grenades would be placed in glass Ball Mason jars which would hold back the safety lever. The safety lever would release upon the shattering of the jar and the grenade would detonate. This particular Improvised Explosive Device was popular with chopper crews in Vietnam, who would use them as improvised anti-personnel cluster bombs during raids. They were easy to dump out of the flight door over a target, and the thick Ball Mason glass was resistant to premature shattering in the air.”
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Mason jar - Wikipedia, the free encyclopedia
Mason jars. Is there anything they’re not good for?