You can use a mosfet switch, the easiest to use being the Burst Avocado. It is programmable for bursts anywhere from 1 (if you have a full auto only machine gun and want to have semi auto) to 12 ( if you want to give cover fire but still be aware of how much ammo you are using) and anything in between. It plugs in where your battery usually goes and the battery plugs into it. It can also replace a fuse, if yours is removable. Some other added advantages include a faster trigger response, and that it makes sure that your piston stops fully decompressed, decreasing wear on your gearbox. There are also a few guns that come 3 burst (The only ones I know of are the Systema PTW's which cost like 1,500).
It really depends on the muzzle velocity (FPS), what the power source is (spring, gas, AEG), and what make/model the gun is.
You will lose velocity
The 'M4 3181 AEG FPS-300 Electric Airsoft Rifle, M203 Spring Grenade Launcher' is a HOT airsoft rifle. Not only does it offer a high power electric machine gun that shoots full or semi auto, it also has a grenade launcher. It is priced around $90, not bad for a rifle and grenade launcher.
Automatic Electric Gun - i.e. airsoft toys guns.
my Willy wonker aka mm nan
an Automatic Electric Gun or AEG is am airsoft gun that runs off a battery to fire bbs instead of being hand cocked or powered by a compressed gas.
In airsoft guns, automatic electric gun. Battery powered airsoft, versus spring powered or gas powered.
Not bad
A good electric airsoft would be a SRC Gen. 2 or 3 XM8..
There are several model names of Thompson Airsoft guns. One such gun is the Thompson M1A1 Full-Metal Body AEG Airsoft gun. Another model is the Thompson Chicago Typewriter AEG Airsoft Rifle. To find other models available check with your local rifle store or search through their website.
it is a very bad idea to have an AEG in snow. it will basically completely ruin the gun.
You can buy an Electric Airsoft Gun (AEG) online or at a sporting goods store.