In addition to changing the fire mode, Burst Fire decreases the fire rate by 9% for most assault rifles, except the AK-12, Remington R5 and Maverick, for which the rate within burst remains the same as the fully-automatic versions. Contrariwise, for marksman rifles, the attachment increases the rate of fire by 25%.
The MSBS assault rifle has an integrated Burst Fire, meaning it fires in 3-round bursts by default, although this can be changed with the Automatic Fire attachment.
In Extinction mode, the attachment uniquely gives the MR-28 a two-round burst function instead of three.
In Call of Duty: Modern Warfare, burst fire is available as a weapon perk called Burst. It is available to the Kilo 141, FAL, M4A1, M13, RAM-7 and Grau 5.56 assault rifles, and to the AUG and MP5 submachine guns. It replaces the fully-automatic mode by three-round burst on most of these weapons, and consequently the player can switch between burst and semi-auto. In the case of the FAL, the perk replaces the only existing semi-automatic mode by 3-round burst.