Which BB to choose!

A lot of people wonder which bb they should use. Most of them use .20g bbs.
There is a wide choice on the market between .12g to .43gs.
It all really depends on how powerful your gun is and how much range you want to get.
Lets say you had a 400fps gun. If you use .20g bbs it will fire at around 400, but if you use .25gs it will shoot at 360fps. You are probably thinking " OMG I want my gun to 500fps!!!!". If you use .25gs the gun will be 360fps, BUT it will have a significantly higher range.

Why? 
The bb receives the energy from the air compression, but then loses it as it exists the barrel. With heavier bbs, the slower it will lose the power, but it will have a lower average speed. The bb has more momentum to than a .20g or .12g bb. It will also be more accurate. anything less than .20 with a powerful gun will quickly exit the barrel but then lose al its momentum as it leaves the barrel.
Think of it as a sprint runner compared to a marathon runner. The sprint runner is going to run very fast in the first 200m+ and then stop because of exhaustion, a .12-.20g bb will go very fast for the first 100 feet and the drop drastically because it would have lost all its energy. A marathon runner can run 40km without stopping. A .23g bb will go further than a .12 or .20.

So, now, Which bb? 

If your gun is 250fps or less I suggest .12g bbs because if you use heavier it will not give enough energy to carry it far enough. If you have a spring pistol then I suggest .12g bbs.

If your gun is 280fps+ (Tokyo Marui for example) then you can use .20-.25 bbs. If you want to shoot long range than use .23-.25 or even .30 Maximum.

If your gun is anything above 330 fps than you can definitely use .25g +. If you have a 400fps .3g should work like a marvelously.

Different types of bbs: .12, .15, .18, .20, .23, .25, .28, .30, .32, .35, .38, .40, .43