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Best M4 loadout and class build for Warzone and MW3

How to get the most out of the M4 in MW3.

The M4 is a weapon returning in Warzone and Modern Warfare 3.

Available to all players thanks to a new feature dubbed Carry Forward, you'll be able to acquire, use, and level the M4 in both Warzone and Modern Warfare 3 if you've acquired it previously in the last game.

It's also available to unlock for anyone who's entirely new to MW3 or Warzone.

In this guide, we'll be going through how to unlock the M4 in Warzone and Modern Warfare 3, what the best loadout and attachments are that you'll want to equip, as well as the best class build you can use to complement the use of the weapon.

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Warzone and MW3 M4 best loadout and attachments

For the M4, we're picking attachments that provide it with extra damage range, stability, and essentially a general collection of add-ons that boost its effectiveness.

Below we've listed the five best attachments for use with the M4 in Warzone and Modern Warfare 3, and after we'll dive into what makes each of them worth picking:

  • Optic: Slimline Pro or Hybrid Firepoint
  • Stock: Corio Precio Factory
  • Rear Grip: Phantom Grip
  • Muzzle: FTac Castle Comp
  • Barrel: Hightower 20" Barrel

The Slimline Pro is a good – albeit basic – call that'll increase the weapon's precision with a clean and easy-to-use red dot sight. There's also the Cronen Mini Dot and Cronen Mini Pro which are the same optic sights functionally, just in different colours of green and blue respectively.

An alternate option we could also recommend here is the Hybrid Firepoint, an optic that has the ability to toggle between a standard, top-mounted reflex sight – much like the Cronen Mini Red Dot – and a 4.3x magnification-scope that will help for the more of the longer sightlines you'll find in MW3's larger maps such as Wasteland and Terminal.

The Hybrid Firepoint optic we suggested as an alternative for its two magnification levels that can be seamlessly swapped back and forth between whilst aiming.

For the M4's stock, we're going with the Corio Precio Factory, granting additional stability and recoil control, making it easier to hit enemies from further away.

With the Phantom Grip, you'll get a boost to your Aim Down Sight (ADS) speed and Sprint to Fire Speed. On the other hand, the Forge-Tac Castle Comp for the Muzzle attachment helps with recoil control and will assist in keeping the weapon steady.

As an alternative, you could always take a suppressor – such as the HMRES Mod Suppressor – so you'll be able to take a stealthier approach whereby your shots don't reveal your location to other players on the minimap.

As for the barrel, the Hightower 20" Barrel is a good shout, giving some high fairly significant boosts to the gun's effective damage range and bullet velocity, whilst improving its overall recoil by just under 10%. There are some hits to mobility and ADS speed, but if it's too much of a decrease for you, other attachments and perks should be able to offset some of that.

The Gunsmith view of the M4 with our recommended attachments.

Generally, how you build your weapons is entirely up to you, and if there's another attachment you think would be good to try, there's no harm in doing so. You can even throw it on and quickly test the gun out at the firing range from any point inside of the loadout, gunsmith, or weapon selection screens.

As a final note, it's worth mentioning that if you're an owner of the Vault Edition of Modern Warfare 2, you'll have access to a large selection of the M4's attachments, including many of the ones mentioned above, right away without the need to level any weapon or complete any unlock challenges.

Warzone and MW3 M4 best class build, vest, perks, gear, and equipment

Since the M4 is a pretty versatile weapon, we're thinking about it being used in a run-and-gun playstyle, albeit with a solid close-range backup option, with the M4 dominating more of the medium-range sightlines.

With the M4 being usable in both Warzone and MW3, each with their own loadout elements, we'll be looking at how to achieve similar build playstyles in each.

Starting with Warzone, let's take a high-level view of the components that make up our perk and equipment recommendation for the M4.

Best Warzone M4 Loadout

  • Perk 1: Scavenger
  • Perk 2: Double Time
  • Perk 3: Stalker
  • Perk 4: Resolute
  • Secondary: Expedite 12
  • Tactical: Flash Grenade
  • Lethal: Frag Grenade or C4

The aim for the perk set here is to provide extra mobility and snappiness, elements that'll complement the M4's higher rate of fire, whilst staying stocked up on various key resources.

The latter of the two will be achieved by equipping Scavenger, a perk that'll allow you to restock ammo, armour and cash from defeated enemies.

Left: The perk selection we're recommending for use with the M4 loadout in Warzone. | Right: The full recommended Warzone loadout for the M4.

As for the mobility boosts, that comes in three forms: Double Time will increase the duration of Tac Sprint and reduce its cooldown time, whilst Stalker will buff your strafe and ADS movement speed, and Resolute will grant a further movement speed boost upon taking gunfire damage.

When it comes to translating this build over to MW3, there's a slightly different set of perks and loadout options to consider, but we'll still be taking a effective-enough approach that'll achieve similar goals via different means - let's take a high-level look at it.

Best Modern Warfare 3 M4 Loadout

  • Vest: Overkill Vest
  • Perk 1 – Gloves: Scavenger Gloves
  • Perk 2 – Boots: Lightweight Boots
  • Perk 3 – Gear: Mag Holster
  • Secondary: Expedite 12
  • Tactical: Flash Grenade
  • Lethal: Frag Grenade or C4
  • Field Upgrade: N/A

Whilst you could pick the Infantry Vest if you want a more simplistic and standard-style COD class with all the usual options you'd expect, we're opting for the Overkil Vest, allowing us to take an extra primary weapon whilst retaining the full suite of perks, with additional weapon handling and reload buffs, at the cost of not taking a Field Upgrade option.

The full class build we're recommending for use with the M4 assault rifle in Modern Warfare 3.

Specifically, the Overkill Vest grants the ability to reload whilst sprinting and increases weapon swap speed, essentially granting the direct effects of both the Commando and Quick-Grip Gloves. The effects don't stack with the perks unfortunately though, so if you don't pick another, you'll gain the effects of Marksman Gloves which isn't a terribly bad pick, but not what we're going for in the first perk slot.

We're picking an option that'll help us stay stocked up on ammo - with the Scavenger Gloves, any enemy you eliminate will drop a pack that once collected, will give a handy injection of ammunition to both weapons, keeping you stocked up as you play.

In the second perk slot, we're taking the Lightweight Boots which will give you an increased base movement and swim speed, whilst our third perk, Mag Holster, will increase reload speed.

Together with the Vest and perk selection, you'll be stay stocked up on ammo both in reserves and in your current mag, with the ability to reload quicker and whilst sprinting alongside quicker weapon swap speed which is perfect for the primary weapon we're taking in the secondary slot.

The Expedite 12 is a shotgun that's also from Modern Warfare 2, but it's one of the highest damage shotguns in the game, and with the Expedite L-Bolt attachment equipped, it gains a much faster fire rate on top of its already impressive stopping power.

Left: A potential custom attachment build you could use with the Expedite 12 shotgun. | Right: The Expedite L-Bolt attachment that, when equipped, will grant a much faster fire rate that'll let you spray and pray faster all whislt retaining high stopping power.

When it comes to lethal and tactical equipment, you can pretty much take whatever you feel comfortable, or what complements the gun being used.

We'd recommend the standard Frag and Flash Grenade combo is a solid choice as always, but you could instead opt for C4 if you want to try out some more tactical placement of explosives that might be handy in some of the more objective-based modes on offer.

As mentioned with the general build of the gun, your preference is always worth keeping in mind when considering what to use, but this loadout should give you an idea for one of the ways in which you could build a playstyle around the M4.

How to unlock the M4 in Warzone and Modern Warfare 3

The M4 is one of the weapons returning in Warzone and Modern Warfare 3 from MW2.

Thanks to Carry Forward, if you unlocked this gun in Modern Warfare 2 - unlocked by reaching player level 4 - you'll be able to equip it in any of your custom loadouts right from the getgo, as soon as you reach level 4 again, this time in MW3.

If you didn't play MW2, you can still unlock this gun in MW3, but it will take a fairly significant amount of time to do so - at least by comparison.

To unlock the M4 here in Warzone and Modern Warfare 3, you'll need to reach player level 55 and complete the associated challenge that will then become available - you'll be able to see this in the weapon selection menu within the loadout screen.

An example of the kind of unlock requirement that will show before you've reached level 55. If you haven't yet unlocked the M4 or haven't yet reached level 55, this is what the gun will show as its unlock requirement.

Once you've got the gun unlocked, you'll be able to equip, level, and customise it to your liking with any of your compatible attachments.


If you're on the hunt for more guides on Warzone and Modern Warfare 3, be sure to check out some of our other guides on offer, such as posts about the best loadouts of other returning MW2 weapons such as the Kastov 762 and TAQ 56, or guides on newer guns such as the Holger 556. Additionally, if you're on the hunt to see what's trending in the current meta, have a read of our best guns guide.

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