KeyMod vs M-Lok
BY Herschel Smith
1 year, 1 month ago
Not a bad article at all from Field & Stream on KeyMod versus M-Lok.
The KeyMod system was invented in 2010 by VLTOR Weapon Systems and Noveske. Its commonly found on the forends on AR-15s and AK-pattern rifles. VLTOR and Noveske designed the system to give a user flexibility in terms of what kinds of accessories they want to attach to a gun and where. They made the system open source so any company could produce it.
Keymod rails are covered in keyhole-shaped slots in a uniform pattern. Each hole has a larger end and a smaller end. To attach an accessory or rail, you place studs (which comes with KeyMod-compatible accessories) in the larger hole, slide the accessory forward, and screw it into place. The studs lock the accessory or rail to the KeyMod forend, and when properly installed, it will not move under recoil.
In a nutshell, that’s why I prefer KeyMod over M-Lok. Ease of installation. I find having to grab the nut underneath the rail to ensure that the screw isn’t spinning on M-Lok attachments supremely annoying, and I’ve had them come loose before.
But to each his own.
On October 20, 2023 at 6:37 pm, Wandering Troublemaker said:
If you want real study data, actual results from DOD testing are out there for your consideration.
Your linked article touched on this testing without directly addressing other key results, such as “return to zero”:
The article said “SOCOM . . . bought a variety of off-the-shelf KeyMod and M-LOK rails, mounted up a bunch of accessories, and put them to the test”–but the actual testing was done by Naval Surface Warfare Center Crane (NSWC Crane), at the request of USSOCOM. Part of NSWC Crane’s testing addressed the question “how good is this system at maintaining ‘zero’ for optics that are detached and reattached?”
They tested comparable MLOK and KEYMOD handguards from 3 different manufacturers (Aero Precision, Seekins, and Midwest Industries)–3 samples of each, times 3 manufacturers, times 2 attachment systems. According to NSWC Crane’s results, MLOK had clear advantages over KEYMOD for “return to zero”, as well as in ruggedness (drop tests and failure load tests).
Average POA shift with MLOK typically was under 2 MOA, often well under. Average POA shift with KEYMOD was generally above 4 MOA, often well over. MLOK handguards were generally less damaged in drop testing than KEYMOD handguards, and the failure load (pulling perpendicular to the barrel axis) for MLOK was two to three times that for KEYMOD.
I found complete briefings on the study results with a search engine using these search terms: ‘NSWC crane’+keymod+pdf. A search on “McGee19427.pdf” should put you on the same briefing slides that I found. I’m sure the briefing slides were based on a more detailed report, but I didn’t find the full report on a quick search.
This article (https://soldiersystems.net/2017/05/05/details-on-the-ussocom-sponsored-keymod-vs-m-lok-test-conducted-at-nswc-crane/) mentions the study and shows some of the slides.
On October 20, 2023 at 9:53 pm, Herschel Smith said:
To each his own.
I don’t use any device like this, KeyMod or MLok, for optics mounts. I don’t really care if a flashlight or sling quick-connect doesn’t hold zero.
If someone is running a Peq-15 with NODS, I can see it mattering, but then IDK how a Peq-15 attaches anyway.