I've had terrible luck with drop leg rigs until I came across the Vapour holster. Low profile and secure, it' doesn't flap about or shift (at least for me) and it doesn't hang on shit in the woods or door frames in CQB. It made even having a drop really work for me. YMMV
Most of the rigs I run have to much crap on the rig to get a pistol clear, if I was going to run one it would be on the rig and not on the belt. It sacrifices load space but what can you do.
In airsoft I don't run a pistol.
Gotta play with it and see what rings your bell man......