I saw an 8x mauser the other day with no markings on the barrel or receiver aside from those in the below picture. Does anyone know what mauser action this may have been based on the proof markings?

Kar98

Seems to be small ring m98, early german sporting rifle with military action.

The marks indicate it was proofed for 2.75 grams of military flake powder (smokeless), with a jacketed bullet.

It is most likely 8x57, but you won't know if it is .318 or .323 until you take it out of the stock and look on the underside of the barrel.

quote:

with a jacketed bullet.

...and those bullets have had steel mantel (Stm.G = Stahlmantel Geschoss).