3WB and billygoat have made good suggestions. You can also take a look at the link below. The OP of the link below, and I had similar issues as you are all having.
Me, personally, I ended up having to open the receiver and clean/light lube and put everything back together. Unfortunately, none of the "quick" solutions worked for me.
I have only been a gun owner for about 1.5 years. If I was able to take apart the receiver and internals and then put it back together, anyone can. Just follow the disassembly instructions in the FAQ. (I think that FAQ link also got reposted in the link below.) As a 'security blanket' I took pictures of the internals before each step - although the link has the pictures you would need.