Call of Duty: Modern Warfare and its free battle royale counterpart, Call of Duty: Warzone, both have a huge number of weapons to unlock and customize. One of the major draws of the game is unlocking a full arsenal of weapons and then grinding each gun up to have cool looking skins and combat-enhancing attachments. Guns can be customized for greater damage, better range, or more favorable handling, but there is more to weapon attachments than just improving the stats of a gun.
Even though there are already tons of weapons available in Modern Warfare, there are many more that can be created with the right attachments. Extremely versatile guns like the AK-47 and AR-15 platforms are used to create a wide variety of different weapons in the real world, and some of those variants can be accurately recreated in Modern Warfare. From SMGs becoming ARs to ARs transforming into LMGs and PDWs, there are plenty of options for changing weapons in Modern Warfare into accurate replicas of real-world variants.
Some of these guns perform much better than others though, so it is important to differentiate between the ones that are there for the fun factor of recreating a real-world gun, and ones that can significantly boost the performance of a given weapon. This is by no means a comprehensive rating of every weapon in Modern Warfare, and there may even be some variants that are missing. With so many unique customization options, there are plenty of weapons to recreate. This list focuses on the most accurate and most effective options.
AR to SMG in Modern Warfare
ARs are the most versatile weapons in Modern Warfare, and that's why they tend to dominate competitive gameplay. For those who want to play on smaller maps and use, quick, mobile weapons, turning an AR into an SMG can sometimes be a more effective middle ground than kitting out an SMG to do more damage. In the mid-range, the M4A1 can become a 9mm SMG with an 11.5" commando barrel, Forge TAC CQS stock, and 9mm magazine. Its damage is reduced, but it makes up for it in handling and mobility. An equaly effective option is to turn the M13 into an MCX Rattler with a Tempus Cyclone barrel, close quarters stock, and.300 blackout magazines.
A heavy-hitting but close-range gun can be incredibly effective despite its inaccuracy, especially in hardcore playlists. For big bullets in a small package, the AK-74u is a great option. It can be made from an AK-47 with an 8.1" compact barrel, skeleton stock, and 5.45×39mm magazine. Keeping larger bullets can be nice, but for the most accuracy to the real world gun the smaller rounds are necessary. The FN Scar PDW does not have that downside though. A Forge TAC CQC barrel and a collapsible stock turn the SCAR into a close-quarters machine that dominates on smaller maps.
The AUG can go from SMG to AR with a 622mm long barrel, the integral 3X optic, and a 5.56 magazine. Unfortunately, while the transformation will look great, it doesn't do a good job as an AR and loses what makes it a decent SMG. The AUG may be a good weapon in the real world, but in Modern Warfare it has been relatively low tier since day one. Especially in W arzone, weapons that do more consistent damage are key, and the AUG just can't keep up.
AR to LMG in Modern Warfare
The AK-47 proves itself once again as one of the most versatile weapons in Modern Warfare because it can become not one, but two different real-world LMGs with the right modifications. In order to turn an unassuming AK into and RPK, all it takes is a 23" RPK barrel, a field LMG stock, a bipod, and a 75-round drum magazine. While this variant is very slow and clunky, it makes up for it with the ability to sustain fire for long periods. That, combined with the crouching and prone stability of the bipod makes the RPK perfect for defending an objective. With a 23" Romanian barrel and all the same attachments sans bipod, the gun is instantly transformed into an RPD.
There is also the option of turning an LMG into an AR, or more accurately, a carbine. The Holger is one of the best and most versatile weapons in Modern Warfare because of its 100-round drum mag and excellent handling, but it can also transform into a G36C, a very effective and popular carbine. With an ultralight barrel, the XRK Axis stock, and 30-round magazines, the Holger can serve as a light and mobile AR. Unfortunately, it loses out on most of its benefits and doesn't do great damage, so it is a purely aesthetic option.
Other Hidden Weapons in Modern Warfare
The rest of these hidden weapons don't fully change their weapon class, but are still serviceable and fun guns with real-world counterparts. The MP5 has several variations. A simple 10mm magazine is one, while adding the subsonic integral suppressor creates an MP5SD. The MP5K can be built with a tactical suppressor, FFS mini barrel, collapsible stock, and ranger foregrip. The MP5 is one of the best weapons in the Modern Warfare and Warzone, and the MP5K is an extremely viable build for it.
With an M16 barrel and stock plus the Burst Fire perk, the M4A1 can become an M-16. However, it might be wise to give up some historical accuracy and choose a better perk than burst fire. While it is not totally accurate to real-world.50 caliber conversions of the weapon, the M4A1 with Corvus custom barrel Singuard Arms Invader stock, and.458 SOCOM ammo is as close as one can get to an AR15.50. The AK-47 can be modernized into an AK-12 with a Spetsnaz Elite barrel, ultralight stock, and 4.45x39mm ammo. Even though it loses some damage, its controllability and handling benefit immensely.
Call of Duty: Modern Warfare is currently available on PC, PlayStation 4, and Xbox One.