37mm APCBC-T projectile core

The seller said that it came in a box of Japanese ammo and Japanese military stuff. I personally think it is a handle of some kind, maybe even AA gun or something, but I don’t think it is ammo. But since I am mostly wrong, I figure I put it here so one of you will say: “It is a very rare Japanese prototype of an secret weapon” or something. So, a handle? This unusual item comes from an unusual gun show - Mt.Bethel, PA Fire Department gun show, correct, right inside the firehouse. It is unusual even by American standards. I thought our European friends might get a kick out of it. How about a Dusseldorf Fire Department Gun Show or London Central Fire Department Gun Show? Sounds good?


It’s definitely a projectile. AP core, it’s missing the light metal aerodynamic windshield on the nose that would give it the more recognizable projo shape. It’s also missing the copper driving band (the groove near the bottom). The caliber would’ve been on the driving band. base has markings, but can’t make them out. Maybe 37mm?

Thank you for telling me I did not waste $15. Here is a better look, the only markings on the base is “22F”. What dimentions are needed for ID?

On my screen, that “F” looks like a Japanese character, but I cannot identify its sound or meaning. It is similar to the character “Getsu,” but is missing one horizontal stroke within the vertical strokes. Maybe someone who really knows something about the Japanese language (I don’t) can identify it properly and put it into context. I could be seeing it wrong, but it looks like there is a verticql line on the right as well as on the left. Take away that line, and it does look like the letter “F.”

John Moss

Looks like a U.S. M51(B1 or B2, hard to tell w/o the windscreen). The references for Jap AP I have don’t show anything like that.

Rick is right. It is the M51 series U.S. 37mm APCBC-T projectile.

The rear portion, or body, is regular steel, with the copper (alloy) rotating band removed. The hole in the base is for tracer compound.

There is a hardened steel “cap” with a blunt point on top of the body, joined at the groove about an inch or so down from the tip.

The Ballistic Cap was a long thin sheet metal point to give it decent aerodymanics in flight, but would be crushed on impact allowing the blunt cap to do the hard work punching through armor. The ballistic cap was seated in the groove around the AP cap.

I think the first M51 was APC without the ballistic cap, but then the M51A1 added the Ballistic cap.

Nice paperweight.

Vlad comes up with some interesting stuff in his travels!

Thanks for kind words. Here is a link to a better view of the whole cartridge

Below, an M51B1 and an M51B2, the main difference is the hardened armor piercing core shape:

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Both these two APCBC-T have a ballistic cap which is screwed on the body, your seem to haven’t got a screw thread around the blunt cap, could be the M51 john spoke about…

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