GL--first thing to check, make sure the screw at the front of the forearm is tight.
The "0" ring is easily replaced. Take the old one out and go to a hardware store--plumbing dept and get a new one.
I've hunted with many Remington pumps all my life. Only had one that developed a rattle and it just needed to have the forearm screw tightened.
Thanks Whelen Nut. I checked the screw and it was tight. That is one big slotted screw. Had to be careful because I don't have any hollow ground drivers that big.
