After the Reapers obliterated the Prothean Empire's warships, the Prothean resistance was forced to develop weapons that did not rely on intact supply lines. The Prothean Particle Rifle is a stripped-down, powerful assault rifle modified to fire without thermal clips or specialized ammunition. Alliance scientists agree that it appears to share some principles with the Collectors' particle beam weapon, although this gun requires a temporary cool-down period if it overheats. An amalgam of two different eras of technology, the particle rifle is still a deadly, efficient weapon.
If used in short bursts, this weapon can take down large groups of weaker enemies like Husks and Swarmers.
This weapon is useful to classes without grenades, as this means you will never have to go to the ammo boxes or use a Supply Pack consumable.
The Particle Rifle is also one of the heaviest weapons in its category, and will be very difficult to get upgrades for. Because of this, one should stay away from this weapon if they are a class that relies strongly on its powers.
Because of the very low initial damage of the Particle Rifle, and its high magazine discharge rate, it is best used on larger, or slower enemies. These enemies will be much less likely to evade the beam, both before and after it reaches its maximum damage. Smaller enemies can be dealt with, but you will have to stay ahead of target to prevent energy being wasted.
The Particle Rifle is best used with an extended clip for extra ammunition, and a piercing mod. The stability dampener has no purpose here since there is no recoil, and the beam will always hit where you shoot, and the scope attachment is also of minimal use.
Be aware you cannot refill the gun since it does not need refilling. Since it's not ammo based, Adrenaline Rush will not give you extra energy to utilise. It will still increase damage done and begin the recharge sequence if the weapon is overheated.
If one wishes to use an ammo power with this weapon, opt for a level 1 or failing that, level 2 ammo type, since this gun does not benefit heavily from ammo like other weapons do. Incendiary ammo works best here, as it means any stealthy enemies like the Geth Hunter, or Phantom will be tagged with an incendiary effect, making targeting them much easier, even while they are cloaked.
Because all geth units are capable of stun, they should be kept at range to allow you to keep up the damage multiplier after the Particle Rifle charges up.
Since the Particle Rifle disintegrates targets upon death, it can be used to prevent Cannibals from consuming enemy corpses and generating armor plating.
The Particle Rifle is very deadly when equipped while using Devastator Mode on the N7 Destroyer. With the magazine capacity increase evolution chosen, Devastator Mode provides a potential 115% increase in magazine size with the Assault Rifle Magazine Upgrade V Mod, allowing the weapon to be fired in overcharge mode for a significant amount of time. You also cannot be staggered, meaning you can keep firing the overcharge beam even while being attacked by strong enemies.
The Particle Rifle's magazine capacity increases to 125 as it levels up. With Devastator Mode and Magazine Upgrade V the capacity maxes out at 268.
Once the increased damage kicks in, the Particle Rifle has the highest damage-per-second of any assault rifle, though this can be difficult if you are taking heavy fire, or are fighting the geth. Due to their stunning, they will often stop you mid-charge unless you are playing as the N7 Destroyer with Devastator Mode activated. Make sure you have a generous distance between you, geth, and melee-intensive enemies, and you should have no trouble bumping up the damage.
Once the Particle Rifle's recharge starts, it will continue on its own if the player switches to a different weapon.
It can also be a very good choice for a Geth Juggernaut, eliminating the need to replenish ammo with its slow movement speed, and it can be alternated with Siege Pulses at range or heavy melee while it recharges. Like the Destroyer, the Juggernaut is also very resistant to stun, making it easier to keep firing.
This weapon is also good with the Awakened Collector Adept, because its passive ability, Vengeful Ancient, has an evolution that can increase the damage of this weapon.
Although it doesn't use thermal clips, an over-heating Particle Rifle can be cooled down by using a thermal clip pack.
To largely negate recharge time and eliminate the cooldown period, stop firing the weapon with 10 or less 'ammo' left. This shaves the 'reload' time by around half.