7,62mm Caseless

There is a caseless 7,62mm cartridge in my collection. It looks similar to the 7,62mm “Minni Round” mentioned on Page 359 of the Volume III (Hackley, Woodin, Scranton) but it has not a hole drilled for machine-gun-links. It shows an overall length of 1.944 inches compared to the Minni Round with 2,160. The diameter of the propellant is 0,469 inches. The tip of the bullet is painted black and it is not magnetic. (!!! No AP).

7%2C62x34-1 7%2C62x34-2

Does somebody has a bit more information about this variant?