Charles Daly Semi-Auto Malfunction. HELP!

[treyn17]

I have a Charles Daly 12 guage semi-auto. It is the turkish made gun under KBI in PA. I picked the gun up from a guy that I have previously bought some other guns from. What he neglected to tell me was the gun was a ticking bomb. Here is the problem. The gun holds 3 shells, one in the chamber and two in the magazine. With one trigger pull the gun will fire two shots off immediatly but will not fire the third. I took it to a gunsmith here locally in middle tn and I believe he said somebody had tried to file on the hammer t shorten the trigger pull, but it has been so long that I can not remember what exactly he said. I have took the gun appart and the hammer catches fine. I have tried to position the trigger where the hammer will not catch. Any help or advice would be appreciated. Thanks