Still having some cycling issues, on occasion a round will hang up on the loading ramp. It's like the shell hits the top edge of the barrel. Even polished the feed ramp and barrel. About the only thing left to do is replace the magazine tube spring. So far the gas rings and O-ring, bolt return spring have been replaced. Barrel and gas ports thoroughly cleaned as well as the trigger group. About the only thing left to replace is the trigger group but everything seems to working as it should. The shell lift ramp seems to work correctly,if anything maybe lifting to high to cause the shell to hang up. Anymore suggestions, at my wits end with this gun. It does not do it every time and it does not matter what ammo is used. Today it was suggested to stretch the magazine tube spring, which we did. It did not help. Just as a Hell Mary, thinking about ordering a mag return spring from Brownells ?