From Halopedia, the Halo wiki

Production overview


Misriah Armory[1]

Model series:



Personal defense weapon[1]



55.6 centimeters (21.9 in)[1]


11.2 centimeters (4.41 in)[1]


29.5 centimeters (11.6 in)[1]


1.3 kilograms (2.87 lb)[1]

Ammunition type:

M490 5.7x28mm HV-AP[1][Note 1]

Feed system:

60 round magazine[1]

Rate of fire:

920 RPM[3]

Effective range:

Close to medium

Service history

In service:

Post-Covenant War conflicts


The M20/Personal Defense Weapon (M20/PDW)[1] is the post-Covenant war successor to the M7 SMG.[2]



Developed as a response to the Insurrection and the Covenant, the weapon is issued to UNSC vehicle and aircraft crews, security personnel, and Spartans who expect close-quarters combat,[2] and has been adopted by a number of UEG security forces.[4]

Design details[edit]

The M20 is visually similar to its predecessor, though it differs in using a new high-velocity armor-piercing round that increases the amount of kinetic energy imparted to the target, specifically developed to counter the proliferation of military-grade armor among Insurrectionist cells and as a response to Covenant energy shield technology.[1] The weapon uses top-mounted magazines of cased ammunition rather than the side-mounted magazines of caseless ammunition used by the M7. Otherwise, the weapon is very similar, featuring an adjustable grip under the weapon and a telescoping stock which can be retracted, allowing the weapon to be fired one-handed. Although the most commonly issued model features a CQB sight attachment, the weapon also accomodated an array of extended barrels, sound suppressors, laser targeters and recoil stabilizers. The weapon is also compatible with kinetic bolts that impart more kinetic energy to the target, and can be equipped with an energy bayonet.[4]


  • Morph SMG: SMG with Morph sight. Advanced tactical configuration used by the UEG's elite bodyguard corps.
  • Projection SMG: SMG with Projection sight. SWAT configuration used by UNSC military police and UEG security forces.
  • Recon SMG: SMG with Recon sight. Personal defense weapon configuration issued to UNSC pilots.
  • Hybrid SMG: SMG with Holoscope. Personal defense weapon configuration used by Sangheili liaison teams.
  • COG SMG: SMG with COG sight. Interdiction configuration used by Marine and Spartan boarding parties.


  • Long Barrel: Increases range of bullet magnetism and aim assist.
  • Laser Targeter: Increases weapon accuracy by reducing bullet spread.
  • Silencer: Firing the weapon does not make the user show up on enemy radar. However, walking still gives away the user's position.
  • Stabilization Jets: Helps control vertical recoil.
  • Kinetic Bolts: Augments knockback and damage against vehicles.
  • Energy Bayonet: Increases melee damage and range, allowing for a one-hit kill against normal opponents.
  • Extended Magazine: Increases both ready and reserve ammunition capacity by up to 40%.
  • Threat Marker: Tracks targeted enemy personnel for a short time.
  • Sound Dampener: Increases effective range and reduces firing signature.


Changes from M7 SMG in Halo 2: Anniversary[edit]

  • Can now be zoomed in using the Smart Scope to have its bullet spread reduced at the cost of added recoil.
  • As of the November 2017 update, headshots with the M20 SMG now deal bonus damage on unshielded targets.
  • Increased damage, killing in 19-20 rounds, (depending on the headshot bonus) instead of 25 rounds.
  • Maximum reserve ammo increased from 180 to 360.
  • Rate of fire is now 920 RPM.

Changes from Halo 5: Guardians to HCS testing[edit]

  • Maximum reserve ammo decreased to 300 (-14.3%).

Changes from HCS testing to Overtime[edit]

  • Aim assist slightly decreased within effective range.
  • Overall damage slightly reduced, including headshot damage.
  • Accuracy slightly increased as the inner reticles no longer bloom outside of the outer circular reticle.


  • The M20 bears similarity of both the FN-P90's receiver-style magazine, and foresight, and the MP7's frame.



Halo 5: Guardians variants[edit]

List of appearances[edit]


  1. ^ Halo Waypoint's article on the M20 SMG states that the weapon uses 5×23mm M443 CLT ammunition, as does the M7 SMG. However, the M20 SMG does not use caseless rounds in Halo 5: Guardians. Furthermore, Halo Waypoint's article also states that the M20 SMG uses armor piercing rounds. As such, the reference to the caseless rounds is presumed to be an error.