SDC is right, the cartridge is an Omnishock, else it is someone’s clever copy of one. I have seen copies before, but usually people don’t bother to peen the lead ball into place as the original Omnishock’s did. Or more accurately it might be an “Ultrashock” which is what their inventor “Alex Goodrich” referred to them as from 1983-1984 before he changed the name to “Omnishock” in 1985.
For simplicity’s sake I’m just going to cut & paste some paragraphs on Omni/Ultra shock ammo from my work-in-progress pistol-AP ammo book:
The original Ultrashocks came in 6rd wooden boxes and they usually had a splash of bronze paint on the projectile tip. If it were an Omnishock it would have the red epoxy coating unless this has been removed or rubbed off?? Back in the early 80’s J&G inc. and B&B (Bumble bee) were distributing for them to both law enforcement and the general public, and B&B was distributing through Shotgun-News and they gained some notoriety that way. The bullet design for either the .38spl or .357mag loading consisted of a standard Hornady 148gr hollow-base wadcutter which was inverted, and which had a hole of about 1/16" drilled into the base of the hollow opening. At this point a #8 metal screw of either steel or stainless steel was screwed into the hollow opening with the threads digging into the 1/16" drilled hole. This projectile would be seated into its casing, and finally have a small #6 lead shot peened by hand (with a hammer) into the slot of the exposed screw head. Some of the later Ultrashock, (and all of the final Omnishock) bullets would have equally-spaced vertical scoring lines extending halfway down the bullet sides to aid in expansion, and a picture of the supposed complete expansion of such a bullet became the logo of the company later on. The final grain-weight of the Ultrashock bullet becomes something between 163gr to 166gr. . In 1985 when the name switch to Omnishock occurred, the entire process remained the same except for the fact that a red epoxy paint was used to conceal the slots on the head of the screw, and the bullet used was eventually something around a 105gr bullet of the same type, which when completed, added up to a final projectile weight of around 118gr, (although they were advertised as 125gr). The brass casings were all commercial, and were either Federal or Winchester with Winchester being the more common. The whole point of Omnishocks was to achieve maximum expansion of the wadcutter and created a large impact surface which would spin and shred as it entered a victim. The whole notion of the steel screw being something of an armor piercing element was a total afterthought, although this screw often would detach and pierce much deeper into tissue or Kevlar than a typical lead bullet ever could. Many tests have shown that the screw and bullet separate nearly half the time without really achieving the wadcutter expanding via threading, and that two impacts would be recorded on a target from both the screw and hollow wadcutter separately. The screw would usually always keyhole when this happened and was not an effective penetrator in this sense. When the screw did engage the bullet properly, expansion was achieved, impact was substantial, and the screw would often separate on impact and penetrate deeper. On Kevlar, a penetration of over 20 layers was reported in tests by the LAPD explosives firearms unit in early 1985. It is safe to say that the bullet was fairly unreliable with questionable quality control in manufacturing which would sometimes result in a separated core, a fragmented impact projectile, or a solid un-separated projectile. Actual