Apropos of nothing, I have never had an 'O' ring fail. I have replaced a couple that started to look ratty in 5 1100s and 45 years. Uh, better make that 4 1100s and 30 years because the senior member has a metal 'O', no, actually it's a 'V' ring. Both of those that got a little fuzzy were on guns that got soaked and got pulled apart and shaken out and/or wiped off and then put together without any anything on the magazine tube, and I could feel the 'O' ring drag when the gas piston shoved it back up into the barrel ring/magazine tube gap the first time.
I have a bunch of spares, that do not look like they will ever get used, mostly bought from Green Top Sporting Goods on U.S. 1 North of Richmond, VA over the years. They used to keep them in a drawer compartment in one of the cash registers. All of them have the light graphite coating Remington put on them, and not one has even begun to dry out. They live in my gun cleaning box for 8 months a year, and then for 4 months two of them live in my wallet. I think they must be neoprene or some other pretty decent synthetic compound.
If you have persistent problems, I haven't a clue what's wrong.