I never seen before this type of box (I am not a mauser specialist).
Is it commun ?
chassepot
Repack, (1944) using 1941 Box (Red Cancellation on Label)…iL (im Ladenstrieffen (in stripper clips); “U” after all the indicators : “Unbekannt” ( lot/maker unknown)
Last ditch salvage of loose ( un-identifiable) ammo, repacked for combat/training use.
Doc AV