What did I get?

I ran across an old friend who is going through a nasty divorce. Anyway, he asked if I still was into guns? He said he had a .22 rifle that didn't have a mag? I asked how much and he said a gift since he didn't know anything about it. It is a Mossberg .22lr, military type green sling, peep sights, excellent condition. I haven't found any numbers on it except for 4 digits stamped into the back of the receiver where the bolt inserts. I would like to find a magazine for it? What is this thing?

OK! I got the point. I will work on getting pictures when I get home. Thanks I do value this board alot.