K-31 Schmidt Rubin

The K-31, properly called the M1931 Carbine, is the last and best general issue rifle in the Swiss Schmidt Rubin line of military arms. Its long receiver and straight pull bolt make it unusual among common military rifles. (There is a 1911 Carbine, but it is easily distinguished by its red plastic bolt handle knobs.) The K-31 is still widely available, but prices have begun to rise as interest increases. Most shootists are favorably impressed with the high quality of workmanship evident on these Swiss rifles. The K-31 fires the 7.5 (7.51 mm) Swiss cartridge. (DO NOT fire the earlier 7.54 ammunition, even if you can find it.) The K-31 is an excellent firearm, well suited to bolt action military matches. The 1911 rifles and carbines, as well as all earlier versions of the Schmidt Rubin, are better left to the collectors.
One member of our team (JP) who shoots a K-31 in matches here wants to pass on two warnings which he has received. The first [Google "SRMB Archives"] concerns the interrupter lug which is located on the operating rod opposite the bolt handle. When this lug "breaks" (sheers off?) at the point of union with the operating rod, the bolt is free to travel rearward when the rifle is fired. The second warning is in German [Google "SBV-ASA"] with a poor English translation, and is more difficult for this editor to read. It seems that cracks may develop at the base of the "bolting device warts" (forward locking lugs). When such cracks are observed, the rifle should not be fired. Should a break occur at the point of the crack, the gas from the cartridge may be vented directly in the shooter's face.