子彈.50,.44,.357點分,咁7.62,5.56呢?

0.50,0.44, 0.357 係英制子彈口徑 ,即係0.50,0.44, 0.357 inch / 英吋直徑子彈.
7.62,5.56係公制子彈口徑,即係7.62,5.56 mm /公厘直徑子彈.
0.44, 0.357 子彈多用作為手鎗之用 e.g M1411, S&W 麥格農左輪手槍.
0.50子彈多用作重型槍械之用 e.g M2重機槍 .
7.62,5.56子彈多用作步槍之用e.g M16步槍

.50 Browning = .50 AE??
7.62x39mm (AK47)= 7.62 x25mm (Tokarov TT-33)??
You have to compare with the whole thing not only the diameter of the bullet.