Looks like a Chinese B3. I have one in .177--basic $20 air rifle. Decent power, but it's an abomination to use. Uncomfortable stock, trigger in the wrong place, about 100lb. trigger pull, rear sight's too far back, no anti-beartrap feature, etc.
It's an interesting gun just to be around, though, since it has sort of an agricultural finish and looks sort of like an SKS mated with an M-14.