Well, I'm very fortunate in that I have a number of buddies that are into guns. They loaned me enough gear that I didn't have to buy anything.
What I took & shot:
- Ruger Mini-14 -- a couple of guys scoffed at this, saying it "wasn't relilable enough for 3-gun." Then it jammed (bad mags), and one of the regular shooters was kind enough to loan me his Ruger SR-556, which shot fine for me, but jammed on the last stage on him. Note, however, that the only reason I was allowed to continue after the Mini jammed was that it jammed on the first round of the first stage. Under the rules, I had never chambered a round in the Mini, so it wasn't "changing rifles during the competition," which is against the rules.
- 1911 with 3 magazines total (1 7-shot & 2 8-shot)
- Remington 870 with Choate magazine extension -- I overheard one guy saying "I guess someone just decided to bring his duck gun." When I piped up with "that would be me," his response: "I wish I'd have thought of that before spending $2K on a new shotgun."
- Extra magazines -- I borrowed 3 30-round AR magazines from a guy at the range. (He was DQ'd on the first stage, but a very, very good sport about it.)
- Shell belt for shotgun shells -- just a plain, ol' duck-huntin' shell belt
- A mag pouch large enough to hold 2 30-rd AR mags
- 2 Mag pouches for the 1911 mags
- Theis IWB holster for the 1911
Was it sufficient? Yes. It was enough to hold enough mags & rounds for every stage without having to run back to the bench to grab ammo.
Could I have carried more? Sure, but it wasn't necessary. We were given a map & round count for the stages. That told me the minimum rounds that I'd need for each stage. If you can find something like that, it'll help you decide what you really
need.