Savage Arms Springfield Model 187TS-R questions

Hi, I am a newbie here and relatively new to shooting(and totally hooked on it! ;D) Last week I picked up a .22 semiauto rifle, on the barrel is marked: Savage Arms Springfield Model 187TS-R Westfield, Mass. USA 22H.S. Short, Long or L.R. as Auto
I have a question and a couple of issues. How old is this rifle? How can i find a manual for breakdown instructions? I took it to the range this past weekend and had a couple of issues. It would fire anywhere from 2-6 rounds and then would not fire. It chambered the next round but would not fire it. When I pulled back the action to check, it would to chamber another round up against the one in the breech. When I put a round in the breech manually it would fire every time, so to me it seems the problem is in the cycling of the rounds. I had the same issue with a full mag(tube style under the barrel), half full, or only a couple loaded in. It seems to be a really accurate, nice rifle, any and all help is appreciated!

Thanks
Mike