Works but need some teflon to get a good airseal
So I went all in on this, and got the orga flathop nub (as recormeded on this site) together with a CJ 220mm barrel, and installed it in my evo. The rubber seems a bit small in the hopup chamber of the evo, and it move around pretty easily, same goes for the barrel. Tested it out, and I lost 0.5J, shooting 1J instead of stock setup 1.5J. After that I used some teflontape on the end of the rubber where it connects to the barrel, and got it up to 1.4j. I still had problems with rubber and barrel have some movement to it, like the hopup chamber was too big for the rubber. Third try, and I applied teflon to the rubber itself, to get a better fit between the chamber and the rubber. This time, it seemed to work as it should, getting me 1.6J. I changed the nub from orga flatnub to the maple leaf concave nub, since the flat nub was to much hop for 0.28 on 0 hopup. The maple leaf nub, also needs to be at 0 hopup but it works.So yeah, for a good airseal in a evo hopup chamber you do need to apply some teflon, and it takes some times to get it just right.