This thread isn't tooooo old so I figured I'd give it a bump. I was looking at an auto 68 special over on the tippmann forum that was claimed to have functioned. The problem didn't appear to be cycle speed (as it is with other blow backs) so much as feeding. The guy was using a qloader to feed it and had to use a piece of bent wire to block the squeegee port. Perhaps the blending issues people get are a result of that port. I know that people have had problems with them in the past and a force feed hopper would likely exacerbate the issue.