From Halopedia, the Halo wiki
- If you are new or rusty to using the M6D in Halo: Combat Evolved, the best tactic to use against Elites is to first hit them with short bursts (or full auto at close range) from the MA5B ICWS Assault Rifle then switch to the pistol for the final blow. This not only saves ammo, but reduces the risk of having to switch out the weapon for another.
- A similar tactic can be done using the Plasma Rifle, which drains shields much faster than the MA5D. Spray a burst till the Elite looses its shields, then go for the headshot.
- The M6D is THE premier anti-Grunt weapon in the game. A single headshot will kill a Grunt regardless of rank, and with a 12 round magazine, a skilled operator can easily eliminate an entire group of Grunts without having to reload. If you do find yourself having to reload, lob a grenade to scatter the Grunts, reload, and resume firing.
- Using the Plasma Pistol and M6D against Jackals and Elites is another great way to save ammo. This combo can be used at all ranges, as long as the Plasma Pistol (especially in its overcharged state) can reach the enemy. This combination serves the player well in all difficulties, especially on Legendary, and can be used against all enemies, from Grunts to Hunters.
- When facing Jackals, fire off a few shots on the Jackal's shield, the Jackal will duck and roll allowing you to get off either a critical headshot or to disorient the Jackal for the kill.
- When firing at shielded Elites, it's easy to tell whether you got a headshot or not. Upon obtaining a headshot, the Elite's head will snap back.
- If you can shoot Hunters in their exposed back with an M6D, they will instantly die with one shot, even on Legendary. The same will happen if you manage to get them in their exposed fronts. This is easily achieved by getting the Hunter to charge you, while back-pedaling furiously, letting it swing at you (exposing its front) and popping one round into it at point-blank range. If you miss the chance to get a shot at its front, side-step its shield swing and put a round into its now-exposed rear
- A well placed shot to the opening on the chest of a Flood Combat Form can instantly kill it. Several shots to its limbs will tear them off, making the form harmless.
- The M6D is surprisingly ineffective against Sentinels, especially those with energy shields. Use a plasma weapon instead.
In Multiplayer, players use the M6D as their all around weapon due to its high accuracy, and high power. In the PC version of the game, it is the best all-around weapon, except in situations requiring vehicle killing, extreme long range elimination, or CQB power. It is capable of killing a fully shielded player in three shots to the head or 5-6 body shots. The pistol also cuts down the usual strife that surrounds sniper rifles; a player won't necessarily kill their teammates for the S2-AM when they have a mid range weapon with a scope, especially one that has nearly 5 times the ammunition available, with more easily scavenged from enemies. It is not uncommon to see entire teams utilizing the pistol and little else.
- When getting into a Pistol battle remember the tried and true strafing tactic; it is harder for an enemy player to hit you.
- Remember that the M6D shots do not travel instantly like a hit-scan weapon would; keep this in mind at when fighting at longer ranges.
- Using the M6D to pull off the Double Melee glitch is very effective when an enemy player is too close to you. Remember though that unlike the BXR glitch in Halo 2 there is a disadvantage, in the form of a possible misplaced grenade.
- The M6D returns in Halo 5: Guardians as a mythic power weapon that can be requisitioned in Warzone and naturally spawns on some big team battle maps as a power weapon. It retains the same stopping power found in Combat Evolved, but is more user friendly due to its hitscan properties. Due to this, leading shots is no longer required. It also bears a slightly faster reload time.