I have an echo1 ak74u with a dual sector gear. I have a 170 spring in it doesn't shoot far but feeds and sprays like a mother. I dump a 450 round lonex mag in about 15 seconds but I've had the bearings for the gears just destroy on me ruining a really expensive piston I need some suggestions about what bearings I should use. No I don't get more than 75 maybe 100 feet out of the distance and before some know it gets on here questioning me about the choice of spring it only cycles half the spring so it can have twice the rate of normal stock fire and has been cronoed at about 260-280. I know its not accurate cause I can't get it to shoot on semi without jamming. Thanks for any and all help in advanced.