The rifle arrived today. It's definitely not a .218 Bee. The Bee case won't enter the chamber beyond the case shoulder. The case head on the rifle's chamber must be just slightly smaller than the .218 case shoulder. Also, the .224 bullet will enter the muzzle easily, so I'm thinking it must be a 6mm or 25 caliber. Any suggestions as to what the caliber might be while I find my cerrosafe and do a chamber cast and slug the bore? Is there any kind of European rook cartridge about that size? There isn't a proof mark or any kind on the gun, at least above the woodline. The wood has the usual handling marks, but it's generally smooth to the touch and the metal has a general patina but no rust or other damage. The bore is usable, I think. Once I see what the caliber is I'll have to shoot it to see how it performs.