Glevum has got it nailed !!!
8cm projectile for PAW 600. (PAW = Panzer Abwehr Werfer), there are several different designations for this weapon and round.
The PAW 600 was a "lightweigt" AT piece operating on the high - low pressure principle.
The hollow charge shells (modified 8 cm werfergranaten) were fired from cartridge casings (modified from the cases used for the 10,5 cm LfH 18) equiped with a pressure regulating plate designed to feed pressure behind the shell gradually, thus radically reducing recoil (making a, relatively, lightweight design of the piece possible).
Although looking like a very flimsy PaK like contraption, the piece was not true artillery but not a mortar like weapon, recoilless gun or rocket launcher either.
The weapon was designed to fill the gap in effective range between traditional PaK and the likes of the PzFaust/Schreck, it would have operated to a max range of about 750 meters.
I'll post some more pics next week as I have no acces to my pics from my current location.
Glevum....the floor is yours now!!
Regards,
Menno