A heavy-duty semi-automatic rifle favored by only the most elite marksman, the M-99 Saber is jokingly referred to as "The Big Iron" for its sheer stopping power. Each M-99 Saber is designed specifically for its owner, making it one of the Alliance's more expensive weapons.
Depending on the player's preferred style, the Saber may be a viable weapon to use even with power-dependent classes like Adepts. Its weight will still slow power cooldowns considerably, even if no other weapon is equipped, but the damage it deals compensates for this. The downside is this type of setup relegates the player to a long-range role out of necessity, because the Saber's sniper rifle-like qualities limit its use at close range.
The Saber is arguably best used with a Soldier or Infiltrator, where they gain huge damage bonuses from utilising their signature powers (Marksman, Adrenaline Rush, or Tactical Cloak). Marksman improves accuracy, recovery time (from each shot fired), and headshot damage, making the rifle perform much more effectively all around, and Adrenaline Rush allows double the shots to be fired while increasing damage by 50-70%. Tactical Cloak gives a massive damage boost of up to 80% to the Saber, but only for 2-3 shots, effectively sacrificing some accuracy.
Unlike most assault rifles, the Saber has a delay before the crosshairs shrink back to their normal level of accuracy. This delay significantly affects one's ability to fire it quickly, especially when not using cover. The Marksman power counters this partially, but the rate of fire should still be moderated to maintain maximum accuracy and damage output. This delay can also be fatal if under duress, as it may give enemies the time they need to take you out.
By adding a stability dampener and a scope, the Saber can quickly line up headshots. get into close quarters situations, as it lacks the damage reduction from hip-firing that affects sniper rifles like the Viper.
The damage of each shot is wasted when aimed at the shields of Guardians. To counter this, a Piercing mod will stop any chance of shots going to waste, but this will have a significant damage reduction when hitting them.
If using it with the N7 Destroyer soldier, Devastator Mode evolved for increased magazine size or rate of fire can remove one of this weapon's greatest drawbacks, making it a devastating alternative for skilled players.
An effective way to use this rifle is to combine it with the Stasis biotic power, especially if the final Stasis Bubble upgrade is unlocked. Stasis can freeze all unarmored enemies, allowing the user to take a few seconds to line up headshots.