Originally Posted by
brassbanjo
For what it's worth I once experimented by leaving an O-ring soaking in WD40 for a month.
It had no discernible effect, and the o-ring sealed fine afterwards
How the 'O' ring fares depends entirely on what material its made from. There are 3 or 4 relatively common 'O' ring materials, of which at least one, ethylene propylene, will be 'eaten' by WD40.
The fact that you lucked upon one that was not affected, does not mean that all 'O'rings will be unaffected.
Happy Shooting!! Paul.
"We cannot solve our problems with the same thinking that we used when we created them" - Albert Einstein.