http://www.matchsaverz.com/Matchsaverz/Home.html
Honestly, I have tried a few options to have one or more extra shells on my shotgun with mixed results. When Blair asked if I wanted to add a Matchsaverz to my new Benelli M1 Build I was lukewarm. I love this thing!!! It is as billed. A simple, fast way to drop one shell into the gun for 3 gun competition if you run dry or need to swap out loads on the fly. All this fro $25. Highly recommended.