The question was posed on another forum, “How many AR magazines do I need to compete in multigun?”
Good question. The simple answer is, “However many you need to complete the stage.” One can also say that all you need to do to succeed in practical shooting is “Align the sights with the target, and press the trigger.” Correct, but it leaves out a lot of important detail.
The core concept of practical shooting is Accuracy at Speed. Your goal is to shoot as many points as possible, in as little time as possible. Everything you do after that buzzer goes off is timed. Furthermore, the only way to score points in this game is to hit targets. Everything else, moving to positions, clearing malfunctions, and reloading, is overhead.
So, you want to spend as little time reloading as possible.
The ideal solution is to have enough rounds in the gun to complete the course of fire without reloading, plus one spare magazine in case of malfunctions. This isn’t always practical; I’ve seen rifle stages requiring 80+ rounds to complete. If you’re shooting the MGM Ironman, even that won’t always be enough.
I think a lot of shooters over think their magazines a little bit. I have, for instance, seen folks with four or five different types of magazine, used for different situations! I don’t think I could handle all the choices…
After some trial and error, I’ve come up with the ideal setup for my way of shooting. In my shooting bag, I have 4 30-round Magpul PMags, 2 Blade-Tech belt carriers, and one Beta mag. I only use the Beta on long rifle stages with no good spots to reload – a full Beta really affects the handling of my rifle, and they can be finicky in the feeding department. But there have been stages where I’ve been glad of it.
If you don’t want to run a Beta, there are some excellent 40-50 round AR box magazines out there. DPMS makes a pretty good one, as does Tripp Research. Nordic Components has just come out with a PMag extension that holds 45-47 rounds, and apparently CMMG has their own 42-round steel magazine in the works. Any of these would see you through 95% of rifle stages, although I’d still have some 30s in your bag for the reloads.
As always, try many options, use what works, discard what doesn’t.