Ammo is a very important part of airsoft. brand, size, and amount all contribute to the overall rank of the ammo. For instance if you used .30 gram bbs in a pistol they would drop like rocks. But if you used .20 gram bbs in a sniper they blow away. I recommend snipers use .28 gram and everything else uses .23. Also what brand it is might be as important because some brands can break your gun and some can save it! Any body that uses crosman is a moron because crosman is the worst of all the brands! Goldenball however is the best brand and it COSTS LESS than crosman!!! And depending on what gun you have amounts are different. Like say you had a aeg I'd say you should get 10,000 bbs if you have a gas pistol you should get 6,000 to 8,000 and if you have a sniper you should get 5,000.