On one of my shotguns I use "cards" in place of a side saddle. They're velcro backed and (theoretically) you can carry a few and just tear 'em off and slap new ones one as needed. A bit too tacticool, you say? Well, perhaps but it also makes sense which is why I chose them. Moreover, you don't need to dicker around with your gun's hardware.
Here's an example:
http://www.originalsoegear.com/colle...a-shotgun-card