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6 Reasons an M-LOK Rail System May Be the Optimal Choice for Your Build

6 Reasons an M-LOK Rail System May Be the Optimal Choice for Your Build

Posted by MCS GEAR UP on Jul 31st 2023

We all love the 1913 Picatinny rail. Every manufacturer conceivable makes attachments that are compatible with it. Heck, you can even get a bottle opener for your Pic rail.

It is strong, reliable, has tons of attachments compatible with it, and is very secure. It’s also easy both to mount and remove attachments, and very versatile with respect to making adjustments.

So, in pursuing this post, we are not objectively knocking the Pic rail, which has been a staple for over 30 years.

It’s just that there are alternatives, like M-LOK rail systems, developed in 2014 specifically to compete with Pic rail systems, that may be better in some situations.

Now, we’ve covered a breakdown of the M-LOK vs. the Picatinny in a previous post. For a more even head-to-head, see that blog.

Otherwise, if you’re looking for the virtues of an M-LOK rail system for your AR-style build, you’re in the right place.

Low Weight

One of the most obvious, undeniable advantages to an M-LOK rail system is that they’re extremely lightweight.

Now, of course, this depends on the material. A Picatinny rail can be made from aluminum, steel, nylon, or some other polymer (and they commonly are). High-density polymers and steel are the heaviest, but nonetheless, the dense configuration of the Pic-lock system adds a lot of weight.

By contrast, M-LOK rail systems (which are often made of aluminum) consist mostly of free space. They are very thin, have wide slots, and lack the heavy edges of Pic rail systems.

Because of how thin M-LOK systems are, and because of how much of the interface is open space, M-LOK systems are much, much lighter than Pic rail systems, even when they are the same size and length and made of the same material.

Does it make a huge difference? Not really, since a lot of the weight of the build will come from attachments. But if you carry an AR-style rifle for a great distance, every little ounce counts, and M-LOK systems come out on top on this one, especially if the rest of your build is skeletonized.

Reduced Cost

To be clear, this is not to suggest that the M-LOK rail system itself is cheaper than a Pic rail. If anything, that is unlikely to be the case, as M-LOK is newer and in demand.

But, M-LOK systems and technology are licensed free of charge, which has substantially reduced costs for manufacturers that want to develop attachments for it.

So, while the system itself might cost a premium, the attachments that are compatible with it don’t. In many cases they are quite affordable, which can help keep your costs down.

Don’t let concerns about cost or finding accessories and attachments that are compatible with the M-LOK system stop you from doing it.

Better Heat Dissipation

Not a huge consideration, but M-LOK systems, with their more open interface and lighter-density design, are better at releasing heat than Pic rails are..

A sporting rifle barrel can get blazing hot, and a dense aluminum Pic rail can trap heat near the barrel. This can throw off accuracy during crucial moments of competition.

If you do a lot of high-volume shooting and you have a quad rail that will trap heat, consider making it an M-LOK rail, especially if you have a lot of attachments on it.

                         M-LOK systems

More Comfortable (With or Without Gloves)

If you’ve never handled an M-LOK rail system, just look at the image above, which shows an assembled upper with an M-LOK rail built into the configuration.

Do you see any of those harsh Pic rail slots sticking out at the sides (not counting the top rail, which is a Pic rail)?

They’re not there. The whole M-LOK interface is smooth when there’s nothing attached. This makes it so much more comfortable to grab an M-LOK handguard.

Frankly, it’s more comfortable even if you aren’t wearing gloves. Not that it’s a huge deal with a low-recoil round like 5.56 or .223, but if you’re shooting a hard-kicking cartridge it’s pretty uncomfortable to grip a Pic rail while doing so.

M-LOK rails, by contrast are much more ergonomic.

Minimized Profile

Refer to the same picture above. See how the overall profile is diminished because there aren’t any weird angles or ridges projecting from the rail system?

That slims down the overall profile of the weapon platform, which is not by much, but sometimes slim, compact dimensions are worth it. If that’s the case for you, you should go with an M-LOK instead of a Pic rail system.

M-LOK Rail Systems Don’t Catch on Stuff

This one’s a big one and it stems from the same core feature that has been covered in the last two sections.

M-LOK rail systems are smooth and lack the raised ridges of Pic rail systems. By that virtue, they also lack all the sharp corners and projections.

Which means, in turn, that they won’t catch on anything. When you’re loaded up with gear and have a MOLLE vest and pack, you’re likely to have a lot of loops and cordage hanging out.

A Pic rail system, with its corners and projections, is like a tangle of treble hooks. They can and will hang up on gear if you let it happen, which is not hard to do.

Now, what you could do is cover up the Pic rail with rail covers, but there are a few drawbacks to this.

One, rail covers make an already heavy rail system heavier. Two, they make a Pic rail even worse with respect to heat dissipation, and three, they eliminate mounting points which are the purpose of the rail system in the first place.

Not to mention you need to pay for them.

Alternatively, you could just get an M-LOK rail system and leave it open. No rail covers are needed; they won’t hang up on your gear.

                      M-LOK systems

Quality M-LOK Rail Systems

These are all the top reasons that an M-LOK rail system might be a good choice for your build, or just to update your existing rifle.

If you’re looking for one, check out our collection via the link above. We carry a wide range of M-LOK systems and rail sections in different sizes and finishes (including free-float systems), but if you don’t see what you’re looking for get in touch with us at