How often should one replace the breach seal in a .25 Marauder? I've had the gun since I think April or May of 2015 and I've probably put 3000 rounds through it since then. (On a side note: I never realized how much I enjoy shooting until getting this gun!) I'm just wondering if maybe it's time to replace the seal. It seems to be functioning OK, but I'm just curious if there is some established, accepted frequency that everyone else knows about that I don't know about. Seems like it is a wear item as the pellets and/or bolt are routinely rubbing against it.