I have a Short Carbine Style, Small Ring Mauser type rifle marked Fabrica De Armas 1916. The cock on closing bolt has two opposed locking lugs, and Commission 88 style no gas shield cocking sleeve and the Bore is about 7mm. Floor palate and trigger is K98. Furniture is very nice full length out to the end of the barrel, as is the upper guard. All other markings are very small inspection cartouche type and a 4 digit SN. No Caliber Markings at all. What is it?