Well, I tried using magnets on my foam blaster, only to find that there is no metal in it at all, but rather plastic, so I guess I won't be securing it in with magnets.
You mentioned that your strap closes with a push-snap, do you un-snap the strap every time you put the gun in, or do you just pull the elastic around the gun? I'm going to use this method on my holster, but am just wondering if the snap is necessary or not, otherwise I'll just rivet in both ends of the elastic.