KeyMod vs MLOK

It can be great fun being able to play with and modify the attachments and AR-15 accessories for your rifle. What’s more, you have a virtually unlimited amount of customization with all of the AR accessories available on the market. A decent bipod, flashlight, sight, and hand stop can help you get the most out of firing your rifle, but you have to be able to mount those components.

In this article, RailScales is going to share the pros and cons of the KeyMod and the MLOK rails systems so that you can decide which is best for you. Each mounting system has its own specialties as well as its own pros and cons, because like with everything in life, no system is ever “perfect.” However, we can help you find the best rail for you and your shooting needs.

KeyMod and MLOK Comparison

A Brief History

For years, the standard accessory mounting system on AR-15 rifles has been the Picatinny rail. To this day, the Picatinny rail is one of the most widely used rail systems in the industry, even though it poses some distinct disadvantages that the KeyMod and MLOK systems can resolve. Nonetheless, the Picatinny rail system is still widely used because of its straightforward and easy-to-utilize accessibility.

One of the disadvantages of the Picatinny rail is that it can add some unnecessary weight to your rifle, bulking it up in a way that’s not beneficial to your use of the gun. Placed on the front end of your rifle, it can make your AR-15 a little nose heavy.

Due to this single inconvenience, two innovative new systems were designed and distributed throughout the industry: Thus, the KeyMod and MLOK rail systems were born of a need for a better, lighter, and more versatile mounting system.

Both systems made the promise to cut back weight and add a wider range of mounting capabilities. Both systems also provided the ability to attach accessories to the handguard and did not require installing a Picatinny rail across the gun. The ultimate advantage of both the KeyMod and the MLOK is that you can add accessories to your gun exactly where you want them without any excessive weight addition.

Which Rail System Is Better?

This is the one-million-dollar question, and it starts with your wants and needs. While answering a question with a question is never ideal, it’s important to consider something: Which system fits your needs the best?

When both systems were launched, there was a fierce comparison between the two rail systems across the gun industry, but one must come out on top; it’s how the world works. With that being said, we’re going to share a brief history of each rail, as well as a brief overview of each of their specialties. Then, you should be able to make a decision on your own as to which rail system is the best for you.

The KeyMod Rail

As a universal interface system for firearm accessories, the KeyMod rail was designed to supersede the MIL-STD-1913 rail. The term “KeyMod” was coined by Eric Kincel when he worked for VLTOR Weapon Systems. The “key” related to the keyhole profile of the rail, and the “mod” referred to the modular accessibility of the rail. As an open-sourced design, the entire firearm industry is free to use and distribute KeyMod rails in the public domain.

KeyMod Pros

• The rail system is smoother, and will not get snagged on seat belts, webbing, or other fabric that is brushed against the system
• You add the rail system where you need to mount your accessories; nothing more, nothing less
• The biggest benefit to the KeyMod rail system removes a ton of unnecessary weight compared to the Picatinny system
• The system is slimmer than a quad rail setup, which also helps with weight, and may be easier for you to grip

KeyMod Cons

• You will need specialized tools to mount accessories and upgrades. On top of this, cheaper accessory mounts may not conform to KeyMod specs.
• There are also, relative to the MLOK, fewer accessories designed for the KeyMod mounting system, possibly because of the fact that the MLOK system is a bit more durable than the KeyMod. There are still plenty of accessories built for KeyMod rails on the market, but if you’re in the market for a certain accessory, it may be a good idea to check if it will fit onto your firearm.

The MLOK Rail

The “MLOK” acronym stands for “Modular Lock”. This rail system is a free-licensed firearm rail interface system that is patented by MagPul Industries. It was developed by MagPul’s design team, which consisted of five individuals. The MLOK design enables gun owners to attach accessories in the “negative space” mounting points.

In late 2007, MagPul revealed a prototype of the MOE slot alongside their Concept Rifle (later known as Adaptive Combat Rifle). Later in 2009, MagPul released the MOE slot systems as a feature on their MOE handguards. Shortly after, the compatible accessory mounts for the Picatinny system were able to use the MOE system. As the MOE system feedback rolled in, MagPul reconciled the system’s shortcomings and drafted the MLOK system in 2014.

The MLOK system is made up of slots, not keyholes, and T-shaped nuts that lay across the slot and lock the accessory into place. Instead of making their design open-source, MagPul decided to go with free licensing to any manufacturer that obtains permission ahead of time.

MLOK Pros

• The MLOK offers a slimmer profile than a quad rail, which can help cut down on weight
• Especially in comparison to the Picatinny rail, the MLOK rail removes the weight of unused rail sections by offering negative attachment spaces for accessories to connect.
• The MLOK rail is Magpul backed and supported.
• MLOK rails are more durable and reliable than KeyMod rails and retain their accessories better. More on this later.

MLOK Cons

• The MLOK also requires extra tools to mount accessories, although they’re generally easier to mount because all that it requires is a basic set of Allen keys.
• It can feel somewhat technical to mount and dismount accessories the first few times you do it; thankfully, there are a number of tutorials and installation guides available to help you comfortably install your first few accessories and get used to the process.

The Difference Between KeyMod and MLOK

For years, both the KeyMod and MLOK system were neck and neck for reliability and durability for use. However, the backing of Magpul behind MLOK and a specific USSOCOM report established MLOK as the best.

Of interest in the report is that 100 percent of the time an MLOK system with attachments was dropped, it kept the attachments mounted. On the other hand, the KeyMod system was only successful 33 percent of the time at keeping accessories mounted. This does not mean that KeyMod designed rail system is flawed. This simply means that in this report, it did not perform as well as the MLOK system.

Ultimately, the decision is up to you. Your rifle usage and preferences trump pretty much everything. If the KeyMod rail is effective for you, use it. The same goes for MLOK.

Use what fits your needs.

RailScales: The Best AR-15 Accessories

If you’re in the market for a new AR-15 accessory to attach to your new rail system, Rail Scales offers a variety of attachments for your rifle. It’s no surprise that as you upgrade your rifle you want the best to improve your shooting performance, whether that be scales, a sight, or a hand stop. No matter what you need, shop Rail Scales online now to find the best AR accessories online.

RailScales.com is a one-stop-shop for top-quality AR-15 products. Our comprehensive product range includes AR-15 grips, sling adapters, and G10 rail covers compatible with both KeyMod and MLOK. Our G10 rail covers serve as a reliable handguard shield, protecting your hands from the heat produced by the barrel and gas block. If you're looking to enhance your AR-15 grip, you can choose from our range of RSB, Anchor, or Karve.

At RailScales, we take great pride in offering superior products made to the highest standards of craftsmanship. We guarantee that every product we offer is made in the USA, assuring our customers of their quality and durability.

Our mission is to provide our customers with the best possible shopping experience. We have a dedicated customer service team that's available to help you with any questions or concerns. At RailScales, you can trust us to deliver top-quality products that are unmatched in the market.