Double Tap is a second tier perk in Call of Duty 4: Modern Warfare, Call of Duty: World at War and Call of Duty: Modern Warfare Remastered, it is also featured as a ThrowbackBasic Training in Call of Duty: WWII, that decreases the delay between bullets by one third of the original delay, effectively increasing rate of fire by 33%. It has no practical effect on most semi-automatic weapons and to players who do not have a fast trigger finger (such as the SVT-40, G3, or M14). Some slower firing weapons such as the M1 Garand and the M1014 may benefit noticeably from this perk. Weapons that benefit most from the perk include Bolt Action Rifles, as the cycling of their bolts is increased, leading to a higher rate of fire from the weapon. Pump action shotguns benefit also, as the rate at which the shotgun is pumped is increased.
Due to a firecap being input on pistols and semi-automatic rifles (at 625 RPM) in Call of Duty: Modern Warfare Remastered, Double Tap is heightened in usage, as Double Tap allows the player to fire close to the original values of Call of Duty 4: Modern Warfare.
Double Tap functions best on slow firing automatic weapons with high damage. Examples of this are the M60E4 and the DP-28. It can also be used to a certain extent on weapons with already high rates of fire such as the P90 and the PPSh-41, to create weapons with incredible amounts of fire power.
A disadvantage of the perk is that it can increase the recoil on guns, which can make them uncontrollable. For this reason, it may be advisable to get as close as possible to the enemy before firing, in order to have the largest chance of hitting them. Steady Aim can be used in conjunction with Double Tap to help reduce the recoil when hip firing. Another disadvantage is that it empties a weapon's magazine faster and uses up more ammunition. Because of this, Bandolier is an advised perk to have with Double Tap, to compensate.
"Greatly increased fire rate of weapons. Bonus: significantly improved hip-fire accuracy."
— In-game description.
Double Tap returns in Call of Duty: WWII as a Basic Training that is limited to be used in the Throwback Moshpit. The Basic Training increase the player's weapons' fire rate and improve their hip-fire accuracy.