Best MW3 M13B loadout and class setup

Looking for the best M13B loadout in MW3? The full launch of Call Of Duty: Modern Warfare 3 is now past us, and players are busily wading into the largest armory of guns and weapons that Call Of Duty has ever seen. This is thanks largely to the Carry Forward system, which means all the guns from Modern Warfare 2 are also available in Modern Warfare 3. And one of the most popular and powerful guns carried forward is the M13B Assault Rifle.

The M13B's blistering fire rate combines with exceptional recoil control to make it one of the easiest and deadliest Assault Rifles in the game. Below we'll show you how to push the gun's limits to the max with our best M13B loadout and class setup in MW3.

Why use the M13B in MW3?

The M13B is a lightweight Assault Rifle with the second-fastest rate of fire in its class (surpassed only by the FR Avancer). With such a high fire rate, the time-to-kill is very low despite the low damage-per-shot.

But the real reason why the M13B is so meta at the moment is its incredibly high accuracy, which - when combined with the right range-extending attachments shown below - results in a laserbeam-like Assault Rifle that feels like it has zero recoil.

Best M13B loadout in MW3

• Muzzle: Harbinger D20
• Barrel: 14" Bruen Echelon
• Laser: VLK LZR 7MW
• Magazine: 45 Round Mag
• Optic: Cronen Mini Pro

This particular M13B loadout is so strong, we haven't changed it one bit since we first put it together for Modern Warfare 2 back in 2022. This build leverages the M13B's fantastically low recoil and high fire rate to eviscerate enemies at very long ranges for an Assault Rifle. With an extended magazine, a clean optic, and the VLK Laser for enhanced mobility, any downsides of the base M13B seem to simply disappear with this particular loadout, which is why we consider it the very best.

Muzzle: Harbinger D20

The Harbinger D20 is a very popular muzzle attachment across lots of different Assault Rifle builds, but it really works wonders on the M13B. As well as the obvious benefit of keeping you off the enemy's radar, the noticeable boost to bullet velocity, range, and recoil control makes it among the best Assault Rifles to use at long-range.

Barrel: 14" Bruen Echelon

The 14" Bruen Echelon Barrel is another excellent range-extended which not only makes the M13B excellent at a distance but also improves its reliability at mid-to-close range as well. Just like the Harbinger suppressor, you also get the benefit of even less recoil. It's these two attachments together that turn the M13B into an absolute laser in Modern Warfare 3.

Laser: VLK LZR 7MW

The above two attachments are fairly heavy, so to speed the M13B's handling stats back up you should equip the VLK LZR 7MW to this loadout. This laser does an amazing job at speeding up the rifle's ADS and Sprint-To-Fire speeds. Just be aware that the laser is visible to enemies while you're aiming down sights.

Magazine: 45 Round Mag

Given the M13B's naturally high fire rate, an extended magazine makes perfect sense. Particularly in Modern Warfare 3, where enemies have 150 health instead of MW2's 100. The 45 Round Mag hits the sweet spot between magazine capacity and handling for us.

Optic: Cronen Mini Pro

Finally, although the M13B's ironsights aren't the worst on offer, we highly recommend you attach a clean Optic such as the Cronen Mini Pro, because it'll make fights at longer ranges much easier. And that's the whole point of this zero-recoil M13B loadout, after all.

Best M13B class setup: Secondary weapon

Lockwood 300, Renetti, WSP Stinger.

Given the M13B's effectiveness across all ranges, it's not necessary to use the Gunner Vest to get a second primary weapon for this build. If you do want to do that, we'd recommend a powerful Shotgun like the Lockwood 300.

But otherwise, you'll be just fine using a Renetti or WSP Stinger sidearm for use at very close quarters fights where the M13B's handling and time-to-kill might not be quite enough to compete.

Best M13B class setup: Perks and Equipment

Frag Grenade, Battle Rage, Infantry Vest, Commando Gloves, Lightweight Boots, EOD Padding.

When it comes to perks for this M13B class, we like to keep things simple. The Infantry Vest is a great pick for the improvements to mobility and Tac Sprinting. The Vest also dovetails well with the effects of Commando Gloves, allowing you to reload while sprinting.

Our pick for the Boots is probably the Lightweight Boots for extra movement speed, although you can certainly opt for a stealthier approach with the Covert Sneakers instead. And for the final gear slot, the EOD Padding will mitigate explosive damage from enemy Semtex and Frag Grenades, allowing you to engage them on your terms with your devastatingly powerful M13B loadout.

As for your Tactical and Lethal throwables, equip a simple Frag Grenade and Battle Rage combo to remain alive and versatile throughout any match.

For more Modern Warfare tips and tricks, check out our guide to the best perks in-game for optimal loadouts.

Best M13B alternatives in Modern Warfare 3

FR Avancer, MCW, M4.

The FR Avancer is the only Assault Rifle that beats out the M13B in terms of fire rate, so if you want another option for fast-firing ARs, the Avancer is the way to go. For a more balanced rifle, you can't go wrong with either the MCW or the M4, both of which are among the most powerful and versatile guns in Modern Warfare 3 right now.

That's everything you need to start tearing through matches and topping the scoreboards with the best M13B loadout in Modern Warfare 3. To see how the M13B stacks up against the competition, check out our guides on the best guns in Modern Warfare 3, and the best MW3 loadouts.