I've often wondered if it's possible to have a hard and wear resistant polymer tube machined to be a tap on fit to replace the O-ring. Polish the inside of the fore end tube "slicker than a minnow's dick" so it would slide smooth and quiet and have a more solid fore end.

The Karma bus always has an empty seat when it comes around.- High Brass

There's battle lines being drawn
Nobody's right if everybody's wrong