So, I have been looking at replacing some of my rail systems with something a little lighter. I have mainly high quality quad rails, and a few Troy Alpha "VTAC" rails. I am looking at going lighter, with a plus being ease of attaching stuff to it.

Question:
Which metal rail system do you prefer? M Lok or Keymod?

Choices:
M Lok
Keymod

 

Flip a coin as far as I'm concerned. Keymod accessories are super easy to install where as my experience with mlok has been a little annoying. Everyone has their own opinions on that though so who knows. Can't go wrong either way.

Hard to pass up the BCM KMR keymod if you want lightweight. I've got a 10" on my 14.5" build and it's crazy light and handy.

I like and have/use both.

Like Jus228 I've also had slightly more issues attaching stuff via mlok vs keymod.
However, these things are absolutely phenomenal.

I've used both, I prefer the look and feel in the hand of M Lok.

Most companies make parts for both, except Magpul who obviously doesn't support Keymod, and companies that have set on Keymod such as BCM/Vltor. Though some rail companies have gone to M Lok since it's easier and cheaper to machine, like Geissele (though, interestingly, ALG has a limited Keymod selection)

If you're set on rails/accessories from a certain company, go with their system, otherwise it's pretty much a tossup.

quote:

I prefer the look and feel in the hand of M Lok.

same here. I must confess, though, that I've not delved very far into the attachments to said rails. I'd buy for looks and feel, and luckily - i don't find I'm too limited in what works for mloc over keymod.

quote:

Originally posted by Rustpot:
I've used both, I prefer the look and feel in the hand of M Lok.

Most companies make parts for both, except Magpul who obviously doesn't support Keymod, and companies that have set on Keymod such as BCM/Vltor. Though some rail companies have gone to M Lok since it's easier and cheaper to machine, like Geissele (though, interestingly, ALG has a limited Keymod selection)

If you're set on rails/accessories from a certain company, go with their system, otherwise it's pretty much a tossup.

Actually BCM has approached Magpul about producing a Mlok rail. If you dig through the M4C achieves you can find Paul and Drake discussing it. Only time will tell if they ever do. Also BCM is very insistent that Keymod belongs to everyone. Eric Kinsel, formerly of VLTOR and now part of BCM open sourced Keymod from day 1.

Back to the OP. I've actually found MLOKs predecessor (and by extension Mlok) to be my preferred negative space mounting solution. While I have 2 BCM keymod (KMR, KMWR-A) rails and mounts, I have found that unless you use lock tight and follow the instructions to the letter, the mount can come free or the rail can get damaged. By comparison I have had an IWI mount on an old style MOE forearm since 2009 and it hasn't come lose once despite a complete lack of Loctite and only inspection for maintenance.

YMMV. You also need to look at what you want mounted and where you need it to sit.

I'd also watch video with Bill Geissele's comments on MLOK and Keymod. I can't find the link anymore but he pointed out the engineering aspects of both. IIRC he pointed out that MLOCK is easier/cheaper to do in plastic than Keymod.

I went with BCM KMR on my SBR and my middy. I like it thus far. I felt the market for KMR would be bigger and offer more options than mlok. Unfortunately, I have yet to run either rifle in a class and that's when I realize what I like and what I hate so I can't give you much more other than that.

So, which will be the standard five years from now and which will be a quaint historical curiosity?
(I have thus far avoided both because the best is not always the one that survives.)

I reconfigured a couple ARs and tried one of each. As far as accessories go, seems like there are more keymod right now, but I have no guess which system will become the standard long term.

There are a few problems to watch out for. Most of these new handguards are very slim and light weight. Evaluate the attachment method on the barrel nut to see if it will hold up to your standard of use and abuse.

Also, I think the slim profile handguards ended up contacting my "low profile" gas blocks under barrel whip (govt profile barrels). I could not get the accuracy under control after the handguard switch. My preferred low profile gas blocks were Daniel Defense with two cross-bolt clamp hex screws.

One rifle has the Bootleg keymod/picatinny handguard from BCM. It contacted the gas block at assembly, so I ground some clearance on the block but it wasn't enough. I tore it apart again and replaced the gas block with the double set-screw block which is shorter on the bottom. Accuracy is now better but even with red Locktite I don't have much faith in the set-screw style gas block staying-put.

My other govt profile has the DD Slim 12.0 handguard, and even with the double set-screw block I don't see enough clearance to avoid contact. That one is still laying on the workbench, not happy with that rebuild right now and not sure yet how to fix it.

FWIW my MLOK is a Geissele, it was pricey but it has better clearance. That one is shooting well and I would buy that handguard again despite the price.

I have also assembled 2 uppers using BCM KMR keymod handguards. They had the same clearance problems as the Bootleg mentioned above. These uppers were built for High Power Rifle competition using the new Service Rifle rules allowing 16" barrels and <4.5x optics. Fortunately, the Rock River barrels came with pinned A2 front sights. I cut the upper triangle sight off with a hacksaw then sculpted the remaining gas block on my bench grinder into the thinnest gas blocks you've ever seen. Those uppers shoot very well

I'm sort the same, I'm about to purchase a new rifle and can have either mounting system. I prefer the thinner guards rifle seem to be coming with these days and really only attach a flashlight when needed (I don't use a rifle as a home defense weapon that's why they made P228s and handheld Surefires). I found the more I shoot this platform less I use a hand stop, have taken it off. I'm thinking KeyMod as it's easy to mount and remove attachments. I guess I just talked myself into KeyMod. Chris

Check the rails and how they feel. One gunshop recently trier to steer me to MLOK based on how the rail felt plain. The MLOK rail was octogonal in shape, and the KMR was more like a cross. Off the rack the MLOK was better, but after some rail covers I don't think there would be much difference.

I prefer Keymod. Slightly easier to install attachments, and there is a wider variety of attachments available for Keymod.

I have yet to have any Keymod accessories come loose, unlike what someone mentioned earlier.

BCM's KMR-Alpha handguards are a fantastic choice for a lightweight Keymod handguard.

http://www.bravocompanyusa.com...-Handguard-s/184.htm

quote:

Originally posted by IrishWind:
Check the rails and how they feel. One gunshop recently trier to steer me to MLOK based on how the rail felt plain. The MLOK rail was octogonal in shape, and the KMR was more like a cross.

"Feel" will vary based on that specific model of handguards, not necessarily by the type of slots. With the different models of both MLOK and Keymod handguards from various brands, some handguards will be more cross-shaped with slots only at 3/6/9, while others will be ocatgonal with slots at 1:30/3:00/4:30/6:00/7:30/9:00/10:30.

I'm not sure why the KMR felt cross-shaped to you... It's a true octagonal handguard with equal slots on all 7 facets (with a pic rail on the 8th facet on top).

In addition, as you pointed out, rail covers will further adjust the feel of the handguard. With the addition of some BCM rail covers on all 7 Keymod sides on a KMR handguard, it rounds the profile nicely and makes the handguard feel cylindrical/tubular.



Even with the more cross-shaped handguards, like Palmetto's in-house offerings, there are covers out there that will round them off. Such as these Midwest Industries Keymod covers, which are nice and wide:



I will concede that the MLOK slots themselves are slightly more comfortable to grasp when bare, if you're not using rail covers or wearing gloves. The Keymod slots are slightly sharper/more abrasive, but still not anywhere near the old "cheese grater" quad rails.

But that's a moot point for me personally, since I put rail covers on all my ARs anyway, for better traction, heat and abrasion protection for my hands, and because I like the way they look.

This message has been edited. Last edited by: RogueJSK,

Easy. We are living in an MLOK world...

quote:

Originally posted by sigfreund:
So, which will be the standard five years from now and which will be a quaint historical curiosity?
(I have thus far avoided both because the best is not always the one that survives.)

Neither. .MIL will crack the code on a powered rail with power supply integrated into the weapon's grip. The attachment method will be driven by the electrical system.

I think it is six of one, half a dozen of another. A lot of the accessory makers make parts for both, and there are some designs for nuts that work with both.

I do slightly prefer keymod because I like the BCM handstop, and vertical grip. But if those were available for mlok I wouldn't be opposed to using that.

quote:

Originally posted by CD228:

quote:

Originally posted by sigfreund:
So, which will be the standard five years from now and which will be a quaint historical curiosity?
(I have thus far avoided both because the best is not always the one that survives.)

Neither. .MIL will crack the code on a powered rail with power supply integrated into the weapon's grip. The attachment method will be driven by the electrical system.

.MIL has an MLOK rail in service, the Geissele 416 rail was approved a few months back. Not sure who for, but it's out there.

Neither.

While I don't like quad-rails either, I like a smooth hand-guard with a mounting point at 6 o-clock in case I want to attach a sling or bi-pod ... maybe (unlikely as it seems) a second one about 1/2 way back on the hand-guard to mount a forward grip.

It took me years to realize that, while these do-dads are cool, I don't use light's, lasers and all the other things that market engineers and designers have come up with to separate me from my money.

Maybe it would be different if I was younger, or lived on a farm and needed to take out fox or coyote's from killing my livestock ... or a night hunter (we call'um poachers) and needed infrared or thermal detection ... or if I was a hit-man, but in both the John Wick movies he didn't use any of that stuff.

I'm probably just turning into my old man.

I like the look of M-Lok, and the fact that it works with polymer, but I prefer the simplicity of Keymod.

Keymod will go by way of HD DVD. M-lok is the Blu-ray of mounting systems.