Last year about a week before deer season here in NJ I was sighting in my 11-87 SPS. Went home, took the gun apart to clean it, and saw the O ring was cracked, I called Remington and they sent me a new one, but Remington told me it was a standard rubber O ring. So to play it safe I went to Home Depot, they didnt have it, so then while on duty I stopped at a plumbing supply store and they had it, I got several of them and good thing I did, cause I did finally get the one from Remington a week after the season, and the one I got from the plumbing store has beed on there for over 1 year, weather it holds up or not I dont know, time will tell.