Make sure you have enough ammo to stay in the battle with spare magazines for electric airsoft rifles. There are several types of AEG magazine: Lowcap, Midcap, and Highcap. Lowcaps hold a realistic number of BBs, and are common for milsim in order to simulate what a real soldier would be able to carry. Midcaps hold more BBs than a soldier would have in a magazine. They are good for storing a lot of rounds without rattling around from the extra BBs. Highcap magazines hold more BBs than midcaps, and are great for when lots of shooting is required. Highcap magazines are wound manually or with a battery system. Highcap magazines can be noisy when running because they contain loose BBs which haven't yet been fully wound into the magazine, but their capacity makes up for this fact.