mauser in other cal from 8mm

[DeLong]

My father past recently and gave me a few long guns. one I cannot identify the cal. A .357 bullet will fit snuggly in the barrel end up to the serrations. Is this maybe a 9 mm ? There are no other marking that are identical except the s/n AF 4646?

[Wolfie]

.357 does equal 9mm. Keep in mind there were several cartridge profiles for the 9mm Mauser. You might want to take it to a qualified gunsmith to have a casting made of the chamber to find out exactly what you have.