For many years, the picatinny rail was the gold standard for attaching things like lights, lasers, grips and other accessories to firearms. While it does work, it does have drawbacks. In addition to plenty of extra weight and bulk, many shooters will complain about the rough feeling it has in the hand. All of these problems brought along the next generations of mounting systems: M-LOK and KeyMod.
Both of these mounting systems use a slot system rather than the rail system of the Picatinny, which means a smoother surface and even more mounting options. Both the M-LOK and KeyMod systems have grown in popularity since their inception, but what are the differences between the two? And is one better than the other?
KeyMod was originally developed as a collaboration between Noveske Rifleworks and VLTOR Weapon Systems in 2012. Their hope was to standardize the attachment system, and they even left it as an open source design in order to allow other companies to make rails and accessories.
This system was designed so that any accessories could be mounted directly onto the rail, unlike the Picatinny that had to be attached to the handguard first. You can even mount picatinny rails onto a handguard where you need as well. As you can probably guess, KeyMod gets its name from the keyhole shaped slots that it uses. 
M-LOK stands for Modular Lock, and was created by Magpul Industries. They introduced this system to the market in 2014, and similar to the KeyMod, it allows a user to mount accessories directly. Magpul created this design as they wanted a system that worked better with non-metal surfaces. The many polymer accessories in Magpul’s product showcase did not work well with the KeyMod, so the M-LOK system was born.
Unlike the KeyMod, the M-LOK is not open sourced, but it is free licensed. This means that other companies can create accessories using the M-LOK system, but only after getting a license from Magpul themselves.
So if these two systems are very similar, which one is better? In 2016, the United States Special Operations Command put these two to the test to see how they compared to one another. They wanted to see which system was better in regards to its durability, drop handling, handling failure load, and repeatability, for the complete report LOOK HERE.
When it comes to durability and handling, both systems pass with flying colors. The biggest differences came in the repeatability testing, where M-LOK came first with the least amount of MOA shift. Another big difference was the drop testing, where M-LOK accessories remained attached 100% while the KeyMod accessories remained attached only 33% of the testing. Because of this testing, the M-LOK was selected for use in their programs.
While the M-LOK came out on top, it doesn’t mean that the KeyMod is a bad system either. Both systems are very functional and each one seems to have its diehard fans. Whichever system that you choose, you will not be disappointed! [/vc_column_text][/vc_column][/vc_row]
