More information needed. Provide a detailed description of ALL markings, their location, barrel length, type of sights, sling swivels if any, stacking swivel if any, cleaning rod if any, etc..
I have one and it is a 7x57 caliber is stamped on the left side of the barrel.
Made in Spain (Oviedo). Impossible to give worth without knowing exact model and condition, and the serial number does not provide that to us. Could be $100-$350 or so.
The Oviedo Arsenal in Spain.
Your Spanish made Mauser rifle could be worth anywhere from $50-$300. Value of any gun is based on exact make, model, condition, and originality.
Juan Carlos Oviedo is number 46 on the Tampa Bay Rays.
You can also get an inside caliper and measure the inside of the barrel. Bore should be .275 in. This is a Mexican Mauser - most of which were 7x57mm.
Caliber can not be determined by serial number.
Oviedo's population is 224,005.
Oviedo was created in 761.
Gilberto Oviedo's birth name is Gilberto Oviedo Hernndez.
Pastor Oviedo's birth name is Pastor Jos Oviedo Rodrguez.
The address of the Oviedo Historical Society Inc is: Po Box 620841, Oviedo, FL 32762-0841