I picked up a Firestar 9mm recently and it's reliability is not good. Usually about once in each clip full of ammo I will have 1 failure to eject. The empty case is usually out of the chamber (not smoke stacked) like it just came straight back with the extractor and the extractor slipped off. If I take off the slide and recoil spring I can chamber a dummy rd in the bbl, pull the barrel out of the lugs and forward and the extractor will hold the dummy round without it slipping out. I thought the clip might be the problem but I get the same failure rate if I fire the gun with the clip lowered 1/8" so I don't think thats it. It's like the empty never gets to the ejector. The extractor hook looks ok to me and looks like it is getting a good hold on the case in the bbl. This is happening with yellow box Remington cheapies and various reloads up to max in both 115 gr and 125 gr. All the reloads are on the Rem cases, I don't have any other kind yet. Any help with this would be appreciated. Nick

It could be just as you suspect (the Ammo). I have found remington yellow/green box ammo to contain up to three visibly different kinds of powder in the same box and batch number.
I wrote remington when I discovered this and they did not reply. If their quality control is like that there is a definite possibility that the loads differ in power.
Try a different quality ammo or hand load some to respectable velocities. Remember that production ammo needs to work in older guns and that 9mm performance has increased in the last few years and your newer gun may be designed to handle these new performance parameters.

The first thing I would so is pull the extactor and make sure the spring is ok make sure it is clean. I just had star super start acting up like that. I cleaned her up and away she went. If that fails the rem brass might be the trouble.

I had a Firestar 40sw with the same symtoms.
It was a loose extractor.

Parts can be hard to find for Stars.
It is a pity, becuase they are good guns.

I had a Firestar .40 that I had to modify the extractor on to get it to work reliably. I put a tiny bevel on the bottom of the extractor to aid in it slipping over the rim of the round, deepened the hook a hair, and tightened the spring a bit. After that, (and polishing the hell out of the feed ramp) it worked beautifully with anything I threw at it. It's amazing what an hour with a Dremel tool can accomplish - but YMMV, so be careful.