Suppressor
Invisible on radar when firing and reduces muzzle flash. Shortens effective damage range.
This classic attachment has not decreased in power one bit over the years, and even in the far future of Call of Duty, it remains a strong and useful attachment for aggressive builds.
By removing your minimap signature when firing, you can operate in close proximity to the enemy team more effectively and safely, and this can score you extra kills, and save you from retaliatory ambushes.
The Suppressor is strong, but it is not a great choice if you’re planning on keeping your enemies at arm’s length.
Make use of the Suppressor for rushing SMG classes, or if you’re playing very aggressively with an AR.
Rifled Barrel
Increases stopping power at long range.
The Rifled Barrel extends the effective range of your weapon by reducing damage falloff. Normally when you fire at a distant target with most weapons, you deal less damage. The Rifled Barrel extends the range your weapon deals its full damage slightly.
Note that this attachment does not increase the damage your weapon does. It simply allows you to deal your full damage potential out to a slightly greater distance.
FMJ
Increases bullet penetration and damage against equipment.
FMJ rounds’ primary use is destroying enemy scorestreaks, though it can also be helpful against a handful of equipment items or specialist abilities that “create” equipment on the battlefield.
It’s a good idea to keep one custom class around that has the Blind Eye and Engineer perks, Smoke Grenades, and an FMJ-equipped LMG. Using this loadout, you can quickly wipe out enemy equipment and streaks with little chance for them to retaliate against you effectively.
FMJ also provides superior penetration through thin walls. Normally piercing light cover reduces the damage you deal, but FMJ rounds can ensure you keep the bulk of your damage intact when you’re firing at an enemy in cover.
Extended Mag
Each mag holds more ammo.
A straightforward attachment, Extended Mags give you more staying power during a multi-target engagement (or a single-target one, if you’re either having a bad day with accuracy or just want to keep a target suppressed behind cover longer).
To get the full benefit from Extended Mags, don’t always reload after a single kill. Odds are there’s a second enemy nearby, and you easily have the ammo to take down a second (or third) enemy when using larger magazines.
The Extended Mag is one distinct difference between Energy and Ballistic weaponry. Energy weapons do not have Extended Mags; see the Fusion Mag attachment instead.
Hollow Point
Increases headshot lethality.
Hollow Point gives you the ability to kill players more quickly if you land headshots.
In practice, this tends to do two things: it rewards extreme accuracy at a distance, and it gives you the chance to score random faster kills at short ranges.
Occasionally when hipfiring at close range, you may score a lucky headshot and win a firefight you might not have. And likewise, at medium ranges, it’s not uncommon to get hit by an enemy and have the flinch knock your shots right into their face.
Either scenario can result in a decisive win in an otherwise even firefight, especially if you are using a weapon that needs very few shots to kill in the first place.
If you’re a crack shot at a distance, Hollow Point can speed your kills slightly, giving you an edge against players in predictable cover where you can pre-aim at their heads, and helping you take down targets that might have escaped gravely injured without Hollow Point.