HK21

The HK21 is a light machine gun featured in Call of Duty: Black Ops.

Campaign
The HK21 is the secondary starting weapon for Hudson on the level "Rebirth." It is very powerful and usually kills in one or two shots to the torso, and has the ability to gib most enemies. It can also be found in other missions, such as "Numbers" and "WMD". Rarely, it can be found with a Round Drum, which gives the player 80 rounds per drum, making for a very effective weapon.

Multiplayer
The HK21 is unlocked at Level 2 to the player, as part of the default LMG class.

The HK21 will kill in 3 shots at any range, or in 2 consecutive headshots, and has medium recoil. It also has no damage drop off at range. This makes the HK21 extremely powerful at medium to longe range. Long-range encounters can be dealt with by firing small bursts. The HK21 is tied with the Stoner63 for the smallest capacity out of all the LMGs so the Extended Mags attachment is extremely useful, as it doubles the ammunition capacity to 60 rounds. The iron sights, while clear and open, can be difficult to use for some. For this reason, some players may find the Red Dot Sight or Reflex Sight useful.

Although the HK21 has very low movement speed, perks like Lightweight are not recommended. Many times it can be tempting to try and counter the sluggish nature of the light machine gun class. However, LMGs like the HK21 are better suited to large amounts of stationary fire, particularly when defending or supporting objectives. For this reason, Scavenger is recommended, as it becomes possible to hold a position indefinitely without running out of ammo. Flak Jacket Pro is always excellent for an LMG class, as your enemies' explosives will be far less effective against you. Steady Aim benefits the HK21 as it improves its CQB capabilities and is useful if caught off guard. Tactical Mask Pro is a good choice if you are trying to hold a position, as none of your enemies' tactical grenades will have significant effect. Sleight of Hand can also be very useful for this weapon, as it dramatically reduces the amount of time needed to reload, as well as improving ADS speed with the Pro version. Warlord along with Extended Mags and a close range sight can be more useful than Sleight of Hand in some situations. Hardened is a very useful perk for any of the LMG's, allowing you to punch through and kill enemies behind cover. The Pro version also reduces flinch by 80%, which is useful if enemies with keen aim manage to hit you while you attempt to defend a position.

Attachments

 * Extended Mag (Drum Mag)
 * ACOG Scope
 * Red Dot Sight
 * Reflex Sight
 * Infrared Scope

Zombies
The HK21 can be found in the Nazi Zombies game mode and can only be obtained from the Mystery Box. It starts with a magazine size of 125 rounds and with an extra 500 rounds. When Pack-A-Punched, it becomes the' "H115 Oscillator" This increases the magazine size to 150 rounds with 750 extra rounds, and gives an increase in damage. The HK21 is somewhat similar to the RPK, but sacrifices a low rate of fire for a larger magazine, higher damage, and higher reserve ammo.

Due to this weapon's high power and large magazine, it is arguably one of the best non-Wonder Weapons in Zombies Mode.

The low rate of fire, very high magazine size and high reserve capacity makes ammo less of an issue for the HK21 than for other weapons. However, the very slow reload time makes Speed Cola useful when using this weapon. Double Tap Root Beer is also useful from rounds 18+ because of the HK21's low rate of fire. The HK21 also hinders the player's movement speed; however this can be rectified by using Stamin-Up. The HK21 can be viewed as a "love it or hate it" weapon. Some will love the high ammo, but the low rate of fire and movement speed will deter others from using the weapon.

Videos
Video:COD Black Ops: HK21 & H115 Oscillator Upgraded Pack-A-Punch Shangri - La Annihilation Map Pack 3H115 Oscillator Overview

Trivia

 * The HK21 has a noticeably slower rate of fire in Zombies.
 * The HK21 in Zombies holds 125 rounds, even though it uses the 30 round magazine model instead of the drum magazine. This high magazine capacity was most likely for balancing reasons, as LMGs in Call of Duty: World at War had more than a hundred rounds in Zombies.
 * The HK21 has a fingerprint on the back of the iron sight.
 * When changing the magazine, if one listens closely, it uses the same reload sound as the PPSH-41 from Call of Duty: World at War.
 * The "115" in 'H115 Oscillator' is a reference to Element 115.
 * Clan Tags are placed on the rear of the iron sights and are completely clear and visible, even when aiming down the iron sights.
 * On the Wii version, the handguard and stock are black, whereas the Xbox, PS3, and PC versions have a somewhat tan-olive color.
 * On the Wii version of Call of Duty: Black Ops, the H115 Oscillator is green.
 * In third person the HK21 has a lot of muzzle flash; however, it is barely noticeable in first person.
 * While in first person, the right side of the trigger guard is missing.
 * In the Create-A-Class display, the character's arm goes through a corner of the gun's stock.
 * The iron sights' range are set to '2'.
 * In the trailer for Call of the Dead, the HK21 can be seen with a Drum Mag and an Infrared Scope. However, this setup does not appear in the map.
 * In the description of the HK21 Call of Duty Elite weapon guide, the HK21 is incorrectly labelled as an SMG.