Those were sold under the trade name "EXPLODER"s or "DEVASTATOR"s
These were available as commercially loaded ammunition as well as projectiles for hand loading from a company called Bingham. I forgot who Binghan had load the ammunition for them. They can be found loaded into all brands of brass. The commercial loader that worked on these for Binghan did not stick to a single head stamp
These were available in 22LR, 30 Carbine, 357 Magnum, 41 Magnum, 44 Magnum, 45 ACP and probably others that do not come to mind at the moment
Looks almost like someone put a primer in the hollow point to make it explode on impact.
The Company line was that these were small canisters of explosive materiel, however they do look like they use a primer seated backwards with a sealant painted on it. Some were sealed yellow and others were sealed in red
The theory was that the primer would be set off upon a hard impact and cause massive damage to the surrounding tissue
With the exception of the 357 projectiles all the primers were large.
Calibers like 22LR and 30 Carbine were handled differently, possibly with the little canisters, but I never experimented with any of the small bores
Way back in the late Seventies and early Eighties these were sold in those little square ads at the back of all the Gun magazines.
In 1981 this ammunition was made famous when John Hinkley fired six rounds in an attempt to assassinate Ronald Regan, the President of the United States of America.
In the assignation attempt four of the six 22LR rounds that Hinkly fired hit people with the remaining two projectiles striking the Presidential limousine and a window across the street. I believe that the only round that exploded was the one that struck President Reagan's press secretary James Brady. The round that struck Brady exploded after entering through the eye socket and striking the back of the cranial cavity
Anyone recognize the name
Brady ?
Shortly after the assassination attempt, ATF sent a letter to Bingham informing them that manufacturing these without an Explosives license would be considered the premeditated commission of a Federal Felony
There were a few Court cases but in the end Binghan lost and this ammunition went from an oddity to Collector status almost overnight
This incident also sparked more than a decade of Draconian firearms legislation attempts playing on the National sympathy for Secretary Brady