Ammunition Magazines for Airsoft Firearms
Made to Look Like the Real Thing
Realistic replicas of the kinds of magazines used in real firearms, made of the same materials as the real magazines (like stamped metal or high impact plastic), are just another feature of airsoft rifles, machine guns, and handguns. They might even have markings on them that are identical to those found on live ammunition magazines.
Since gas blowback magazines, used on the blowback models of airsoft guns, contain compressed gas as well as pellets, the metal used to make them is thicker. These particular magazines usually have a valve on the bottom that is used to charge the cylinder that is inside with gas. The design is created so the magazine looks like and is close to the same weight as a fully loaded magazine for a real firearm.
The Standard Capacity Magazine
There are a few classes of airsoft magazines and they're divided according to the amount of pellets or BBs they hold. The Standard or Standard-cap type of magazine is made by the Tokyo Marui company and fits a wide range of firearms. The Standard magazine holds about 68 BBs that are usually loaded into the magazine by dropping the BBs down a shaft while holding a spring that is used to feed the BBs into the gun. Standard magazines tend to be quiet, they don't rattle and they don't need to be wound like high-capacity magazines. They might be the only option for some airsoft guns. A "realistic" feature of the Standard airsoft magazine is that the number of rounds is closer to the real thing - 20 to 40 rounds in a real rifle and 68 or so in an airsoft rifle magazine.
Mid-Cap and High-Cap Mags
Mid-caps or medium capacity magazines function like a standard magazine but hold more rounds, accommodating between 50 and 190 BBs. They are quiet and don't require winding like the high capacity magazines do. High-caps, or high capacity magazines, hold more than the mid-caps, taking a load of 200 to 1000 BBs. The difference in operation is that the high-cap mags have a wheel that has to be wound every 50 to 100 shots. You load a high-cap mag by pouring BBs into the holding tank and either wind the wheel on the bottom of the mag by hand, or by electric motor.
Going for Real
If you really want authenticity, you could go for the real-cap - real capacity. These magazines are identical to standard magazines but they carry far less ammunition. They are in line with the real versions, so an M-16 Real-cap holds 30 rounds instead of 68, which is standard with the Tokyo Marui versions. You can even get the ultra-realistic magazines that are weighted to the same specs as the real ones. This type of magazines is most often used for military simulation games because of their realistic qualities.
