Going to have a gunsmith investigate this matter but I figured I'd put it out to the board also. I have a Garbi 100 that when both barrels are fired, the left ejector works fine but the right ejector fails to fully eject the spent shell. When I fire only the right barrel, the right ejector work fine.

When using snap caps the ejectors work as they should. Any thoughts on what is going on?

That tells me, that it is recoil induced, and it's probably going to be in the fore-arm mechanism. I have a Remington 1900 that was doing something similar, and it was an ejector spring, in the fore-arm, that had slipped out of place, and I had to disassemble it, and put the spring back in it's proper location.

binko