Polish production /21/ Mesko.
As in 7,62x39 black tip UZ / УЗ = enhanced load, for used in the production and repair of weapons, is used to test the strength of the firing mechanisms/bolts.
VD / ВД - heavy bullet, high pressure, for barrel test.
I dont have PL designations. In plates from old museum Mesko for two othe technologial types [one for helmet test] of ammo i have only name, without “short designation”.
On box from 7,62x25 for test helmets is a text “WZM” = “Wzmocniony” but its only for “enhanced load”.
I have never delved into the beginnings of Russian cartridges of this type.
As in PL prewar, standard bullet, enhanced…, in Mauser 7,92mm and 9x19. I did not see in prewar papers a work about “other shape” enchanced bullets, only very many types short range, but in experimental area.
Back to 7,62, two pulled bullets VD /2, 3/ with a strong crimp in neck case: