OK, Pepper. I’ll rise to the bait.
MBA made a series of “Javelin Stabilized Quiet Rounds” and launchers (pistols) beginning in 1964. The systems were type-classified by the U.S. Army as the M1, and they were at least field-tested in Vietnam. Some sources say they were used operationally in Vietnam, others say they were not. The CIA was also involved in the project and provided funding.
The cartridges held 0.030-inch-diameter Javettes with tungsten heads and threaded magnesium tails to hold a chemical or biological payload. One use was to temporarily put down guard dogs at enemy installations so special forces or clandestine agents could enter, do their business, and then leave with no evidence they had been there. The guard dogs would awake, no worse off. If the mission was assassination, the agent was biological, normally saxitoxin made from shellfish. Death was almost instantaneous.
The Javettes were fired at velocities below the speed of sound from silenced pistols. Because of their velocity and small size, targets were not aware that they had been shot. Impact was below the threshold of pain in almost all cases.
Cartridges were both electric centerfire rounds and converted .22 Long Rifle versions. There are several variations of these, all as scarce as hens’ teeth, including a converted 5.56mm version designed to be fired from an M16. These are discussed in IAA Journal #473, May-June, 2010, and several of the “poision” rounds are shown on the issue’s cover.
Complete coverage of the systems is in chapter 5 of my book, MBA Gyrojets and Other Ordnance, which finally went to the printers two days ago. Thanks, Pepper, for the opportunity to plug the book.