help...semi-auto woes ... now I have a expensive single shot

I bought a American Arms ,Luigi Franchi , Black Magic 20Ga about ten years ago. It is a fun little gun and at 4.6 lbs it is easy to hunt with it all day. Prior to this gun I had a really old 12Ga pump that felt like an anvil at the end of the day.Switching to the 20Ga was a trade off , overall weight -vs- the 12Ga killing power. Needless to say, I put a lot rounds through that gun the first year just trying to improve accuracy.After about 500 rounds I could shoot a pretty consistant 23 out of 25 and runnin bunnies were usually in deep deep trouble... Now I dont hunt much, but killin clay birds is still fun and it fits my schedule better . Since that time Ive put another 1000 rounds on . When it was new it rarley ever dropped a round and then usually that was my fault by not shouldering tight. As time passed though it started dropping more and more until recently it has stopped ejecting altogether. Cleaning has never been an issue ( I think )
The thing comes apart without tools only takes about 10 minutes to clean.
As many times as Ive had this thing apart ( especially Lately )
I cant see anything that would cause the problem.

Has Anybody else had this problem ?

Is there a link to an exploded view ?

Where is the Gas tube ?

Which way does that bushing really go ?