the oring on the brass adjusting/seat retainer screw?
It's usually a function of cleanliness with that one - schmutz gets up in there, adjustments get made, the oring rides across the schmutz. it's not a big deal/uncommon, just try to keep it clean especially sand/hard debris.
Id' be more nervous about the brass adjuster in FRONT of the gun for LPR, I recommend "plugging" that with something to avoid the perfect paint shot going in. I use an '05 matrix rubber detent myself.
I used to bullseye womp rats in my T16 back home, they're not much bigger than the brass adjuster screw