One quirck of the KSC MK23 GBB I have is if you drop the hammer and fire it double action, it's basically a NBB and fires with a little pop, perfect when the suppressor is on. I sniped a half dozen guys from deep inside a dark room, prone behind a ladder, not 30ft from where the guys were, they all thought someone would step on a BB and snap it up to hit them, they were baffled! Was so hard to supress my laughing at how funny it was, they had no idea I was on the same floor as their respawn and was picking them all off as they went for the stairs.
Later in the day I ran 100% Glock 19, racked up piles of close range kills in that building, reloaded from my MP5 mags. Lol, it stayed slung the rest of the afternoon.