If you have a pistol and a couple magazines and a good holster, a carbine/rifle with two magazines and pants with pockets to hold the spare and a shotgun of almost any type you would be fine. A way to hold shotgun ammo is a plus, but I have never seen a "new guy" at these matches that won't be offered all sorts of gear to help him through the day, like shell holders, mag holders etc. If you bring 100 rounds for each gun you will have more than enough for the entire match and probably take a bunch home. I usaly keep round count to around 50 for each, but sometimes folks aren't as accurate as they want to be under pressure.