New to 3-Gun and Buying My First Rig

Decided I want to explore 3-gun shooting. I will be fielding a M&P 9mm, Mossberg 500, and a self built AR-15. I am currently working on getting my first belt rig and have pieced together a Blade-Tech setup for about $180. I have pistol holster, 2 pistol mags, 2 Johnny Clip shotgun shell holsters and a Magpul MagLink for my AR mags. Am I missing anything that would prevent me from starting out? TIA!!

 

You really only need to be able to carry 1 AR mag...and that may not be necessary most of the time. Sometimes a sling may be necessary for the rifle. Ammo, bring extra ammo...although I'm sure you're not going to miss.

I'm not familiar with your specific brand of shotgun shell holders. What is your shotgun reloading technique? That is where you will gain or lose time when dealing with the shotgun.

Good luck and have fun. Your first few matches will have a straight up and down learning curve. There's nowhere else you get to shoot your guns like you will in 3-gun.

 

As locogringo says, depending on your club you may not need an AR mag pouch. I have one but have never used it. You can generally shoot a stage with just the mag in the gun, and if not, a back pocket works about as well as an AR mag pouch for a rare reload on long stages, IMO. A maglink will work great if that's your bag, but it does make the gun quite a bit heavier.

Shotgun you may not actually need carriers or "twins/quads" rigs unless your club's shotgun stages are long. I use weak-hand load and use shell caddies but 98% of the time I don't need to use them, because my 590 holds 9 in the gun and 12 on the gun (butt cuff shell holder and 6-round side saddle) and about 75% of the time I don't have to load any more than what's in the gun. IMO it's so slow to load the shotgun (for me) that it's almost always better to shoot any available targets with "the other gun" (pistol/rifle/PCC depending on stage design and description) so I mostly just shoot my shotgun dry and transition. YMMV, but ask people in your local club and see what they say.

Definitely want good retention/tension on your pistol holster. IMO the Safariland ALS/SLS is a great system for cheap, but a good holster with tensioning buttons/screws will probably work. Running with a full high-cap pistol in a holster is a tall order without mechanical retention. You definitely need good pistol mag pouches if you haven't added those to your list.

When you're starting out, worry more about shooting safely and having fun than outright speed, and basically the only gear you really will probably need is a good belt, pistol holster, and pistol mag pouches.

 

With shotguns in 3-gun the biggest issues are loading, as discussed above, and jamming. Since you are running a pump, you should be pretty well off on the later. Rack it HARD!
With handguns be sure you have enough mags with you. Depending on the club, there can be a lot of shots with plentiful steel targets, which can eat up a lot of rounds, especially when you miss as much as I do! I often just carry two in my normal IDPA mag pouch but put a third in my pocket as a backup.
With rifles the biggest frustrations I've seen are with the longer shots. Just know the range you'll need and be sure you know your hold out to that range. This issue is most common with someone with a red dot and they don't know where to aim on an 8" plate at 200 yards with it. Of course this varies a lot from club to club but it's good to know what you're getting into and have shot a few rounds at the max range beforehand! People's ARs also seem to jamb a lot. Competition is a great place to learn more about your equipment and find ways to improve it after if fails at the most inopportune moment in front of a bunch of other gun people!
Have fun!