Select Fire

Select Fire was a cut attachment in Call of Duty 4: Modern Warfare, Call of Duty: World at War, and Call of Duty: Black Ops. It appears in Call of Duty: Black Ops II.

Overview
In Call of Duty 4: Modern Warfare, it was set to appear on the assault rifles, as proven below. In Call of Duty: World at War, it would have allowed players to switch the fire mode of the STG-44, M1A1 Carbine, and SVT-40 between semi-automatic and full-automatic. In Call of Duty: Black Ops, it was shown to be initially available as an integrated attachment for the Galil. Although this feature was present in Call of Duty and Call of Duty: United Offensive, it was cut from subsequent games due to lack of real use.

It is mentioned in the Call of Duty: World at War strategy guide, which was published before the game's release.

Call of Duty Black Ops II
"Switch to burst or automatic fire with 3 (on PC) / D-Pad. Automatic fire will always have more recoil."

- Create-A-Class description.

In Call of Duty: Black Ops II's multiplayer, Select Fire appears as an attachment for assault rifles and submachine guns. It adds a more controllable burst mode to fully automatic weapons, and a full-auto option to burst and semi-auto weapons. Keep in mind that adding and using full auto mode on single or burst weapon will always reduce accuracy and increase recoil.

Maximum fire rates of the semi-automatic rifles, the FAL OSW and SMR are lowered from 625 RPM and 535 RPM to 468 RPM and 416 RPM respectively for balancing reasons, similar to how the CZ75 had its maximum rate of fire reduced from 625 RPM to 535 RPM when equipped with the Full-Auto attachment in Call of Duty: Black Ops. The SWAT-556 also suffers from extreme loss in range, being able to kill in three hits on fully automatic in only point-blank.

The Select Fire attachment cannot be used in conjunction with the Grenade Launcher or Hybrid Optic in any way. In campaign, it is also incompatible with Rapid Fire and the Suppressor.

Burst Delays
In previous games, almost all burst-firing weapons have a delay of 0.2 seconds between bursts, but in Call of Duty: Black Ops II's multiplayer and Zombies modes, the delay is reduced for most weapons. In campaign, all burst-firing weapons have no delay between bursts (excluding the M1216, since it is technically not a burst-firing weapon, but is automatic and rechambered after each four fired rounds).
 * The Vector K10, Peacekeeper, MTAR, Type 25, M27, SCAR-H (all with Select Fire equipped in multiplayer) and the Chicom CQB (in all game modes) have no delay between bursts.
 * The MP7, PDW-57, MSMC, Skorpion EVO and AN-94 (all with Select Fire in multiplayer) have a small delay of 0.032 seconds between bursts.
 * The B23R (in multiplayer & Zombies) has a 0.08 seconds delay.
 * The M8A1 (in multiplayer & Zombies) and the Colt M16A1 (in Zombies) have a 0.112 seconds delay.
 * The SWAT-556 in multiplayer used to have a 0.2 seconds delay between bursts, but after January 26th's patch it was reduced to 0.18, thus increasing the rate of fire.
 * In Zombies, the Pack-a-Punched FAL retains its 0.2 seconds delay from the previous game.
 * The M1216 has a 0.55 seconds delay to rechamber.

Call of Duty 4: Modern Warfare

 * On the cut Training map, the "M4A1 Carbine Full-A" text can be seen. This refers to fire selection in very early Call of Duty 4: Modern Warfare versions.

Call of Duty Black Ops II

 * In the campaign, the player can seldom find a weapon with Select Fire and Rapid Fire or Suppressor, despite this combination being impossible when customizing the loadout.