HK53

The HK53 is a carbine made by German firearms manufacturer Heckler & Koch. It is a variant of the HK33 assault rifle, and operates similarly to the G3 battle rifle and the MP5 submachine gun, but it is chambered in the 5.56x45mm NATO round and is fed from 30-round box magazines. It is featured in Battlefield 2: Euro Force and Battlefield 3: Back to Karkand.

Battlefield 2: Euro Force
The HK53A3 is the standard carbine issued to the EU Spec Ops kit. It has moderate firepower, low recoil, and a decent rate of fire. It comes with a 40-round magazine, and can be fired either full-auto or in mechanical bursts, though there is no difference in terms of accuracy between the two.

Battlefield 3
The HK53 (labeled as the G53 in Battlelog and on Xbox 360) is a weapon added in Battlefield 3: Back to Karkand expansion pack.

Multiplayer
Only available in Multiplayer. It features three-round burst, full, and semi-automatic firemodes, a moderate rate of fire, moderate damage, and a 30-round magazine capacity with four reserve magazines by default. It is unlocked when the player completes the assignment "Fixing It" which consists of:
 * Performing 10 repairs
 * Killing 1 enemy using the Repair tool