I have a couple of the pearce grip +2/+3 round magazine extensions, and they say it is +2 rounds for .40cal, but there is absolutely no way I'm getting an extra 2 rounds in there. It seems to only extend capacity by one round. Not that its a big deal, but its something i have wondered about. I have tried this on 15 round g22 mags and on 9 round g27 mags with the same results. Any thoughts?