Did you know there are six types of rail systems for your favorite guns? You have the Dovetail rail, Weaver rail, Warsaw Pact rail, Picatinny rail, KeyMod, and M-LOK. But let’s focus on the last two for now. These days, KeyMod and M-LOK are the most popular form of rail on an AR-15, and rightfully so.

But which one takes the crown? You can only choose one for your rifle, so let us weigh the pros and cons of each and determine which one is best suited to your situation.


Back in 2012, all thanks to the experts at VLTOR and Noveske, the KeyMod was designed as a public domain project, allowing all other firearm manufacturers to create their rails without paying for the rights. We’ve witnessed firsthand a boom in the firearm rail industry — a logical benefit to the everyday gun owner.

So, why do so many love the KeyMod system? To start, KeyMod designs are light. When the slightest weight change can affect your stamina and aim, every ounce matters. Furthermore, the KeyMod is compatible with a wide range of accessories, including lights, lasers, foregrips, and bipods. The rail offers you the opportunity to customize your rifle to your heart’s desire.

Picture the door chain on your home’s front door. The large hole accepts the locking mechanism that you slide into the smaller section. That’s similar to how the KeyMod rail works. But you’re not reliant on a more substantial object fitting in a smaller hole. That would be detrimental to performance. Once inserted, you tighten the lug screw and the accessory bracket locks in place. It is a safe and secure method.

Other benefits of the modern KeyMod system include its flying colors on endurance and rough-handling tests, making it ideal for field use and long days at the range. Believe it or not, performance matters when it comes to your handguard, and KeyMod rails steal the show.

There are cons to the KeyMod system, too. Let us explore a few:

  • Minor parts are easy to lose and difficult to replace.
  • During Drop Testing, the accessory rail separates from the handguard.
  • When dropped, KeyMod slots fracture.

The key to the KeyMod system is a firm grip. Do not, under any circumstances, drop your rifle with much force; otherwise, you risk breaking the rail system.


You’ve likely heard of Magpul in your online gun research sessions. There’s an excellent reason, as Magpul is the number one name in firearms and firearm accessories. When VLTOR and Noveske were developing their KeyMod system, Magpul took note. In 2014, they quickly put their M-LOK rail system into research and development.

Like the KeyMod rail, M-LOK is a modular accessory mounting system for rifles that, to most shooters, is a more attractive package — both in appearance and in features. The M-LOK looks fantastic on a gun, and there’s no getting past that. But looks aren’t everything. It’s functionality that we’re after. Instead of the keyholes like on the KeyMod system, the M-LOK uses unique slots designed to attach polymer accessories without fail. The concept is similar. The M-LOK features the slots as mentioned earlier in which an attachment inserts to a mounting bracket, then tightened down. The critical difference is in the bi-directional swivels of the locking lugs. When tightened, the lug rotates, holding your accessory of choice firmly in place.

How does the M-LOK perform?

Let us look at the pros of the M-LOK system, including the fact that it was designed by one of the top rifle accessory companies on the market today. Here are a few other notable advantages the M-LOK has over the KeyMod rail system.

  • Widely available
  • Withstands cyclic forces
  • Secures accessories against high vibrational loans
  • Accessories remain thoroughly attached when dropped

To most, Keymod is a thing of the past at this point. MLOK has been adopted by the military, as well as the civilian market, and tests have proven the MLOK system to be more duraable, with a better return to Zero. Better function, and better form? What’s not to love?