I inherited some ammo from my father when he passed away and am trying to identify the caliber. I think he had a Norinco SKS that he used to fire it from. I have about 400 rounds, on stripper clips of 10 rounds each. The stripper clips are wrapped in brown paper and "packaged" 3 clips or 30 rounds each bundle I think. Havent gone through it all yet. The only markings I can find on the rounds are the headstamp numbers "31" and "76" opposite each other. I have tried to attach the pics. Sorry if they are blurry. I appreciate the help guys. Trying to determine what it is so I can get some type of value.