Squad Automatic Weapons are lovely to have. This is the CA249 Classic Army replica. It will accept a magazine or, with a minor conversion, a belt-fed backpack. This one was advertised at $850, which is pretty well way far out of the range of what I'm willing to pay for a toy gun. It's probably a bit too powerful for our purposes, as well... wouldn't do to go puncturing friends with minor artillery.
I honestly didn't mean for that to sound dirty.
Sometimes, though, you need something... more. Something that says "Almost Laughably Overarmed". Something that says "8,000 rounds per minute". Something that says "Action Movie Cliche". For those times, there's the M-134A Vulcan Airsoft Minigun.
I saw one of these destroy a television at close range on YouTube.
These weapons are lovely, but I can't in good conscience see myself introducing them to any kind of LARP event. What I absolutely hope to make use of are these USB-controlled drone airsoft turrets:
Imagine the possibilities! If they had one of these in Ye Olde Alchemists Shoppe, I might think twice before picking the lock and gleefully looting.
Also a nice option are these spring-powered, reusable Airsoft Claymore Mines.
Check the corners, kids! You can't shoot zombies if a mine has turned you into pink mist!
Up next is my personal favorite: the Sakakibara-Kikai Land Walker, a bipedal robotic metal exoskeleton. Mounted on both sides of the head are multibarrelled cannons that fire soft foam balls. It operates using a 250cc 4-stroke engine and stands 3.4 meters tall. It's 1000 kilograms of Airsoft Mecha joy!