The M-Lok vs. Picatinny debate has waged for almost a decade with very heated opinions (not an exaggeration) on both sides.
I don’t aim to add fire to this quarrel, but rather objectively discuss the merits of both systems as viable options that ultimately come down to the end user’s preference.
The 1913 Picatinny rail has been the standard mounting solution on firearms for decades.
Since its inception, the Picatinny rail system has seen wide adoption from the military, law enforcement, and the civilian market.
Due to the wide adoption, there are virtually unlimited Picatinny accessory options ranging from essential to absurd.
During the War on Terror Picatinny earned its stripes as a rugged mounting system, remaining intact despite the abuse, falls, drops, and other forms of beatings throughout the war.
Users discovered that a good optic with a good mount would maintain zero on a Picatinny rail despite harsh treatment.
Magpul released the M-Lok rail in 2014 to offer another mounting option for users in the form of a lighter, sleeker rail design. Both the M-Lock and Picatinny rails have their benefits and drawbacks, let’s get into it.
1913 Picatinny Rail System
The Picatinny rail is derived of a slot and rail design, giving the user an incredibly secure method of attachment for grips, lights/lasers, but most importantly optics.
The method Picatinny utilizes provides multiple locks, from the initial slot and rail to the edges of the rail.
This led to reliable locking for Picatinny attachments, most importantly allowing optics to maintain a tight zero. That is why to this day, most if not all M-Lok rails have a top Picatinny rail.
Quad Rail System
The quad rail is probably the most recognizable representation of the Picatinny rail system.
While very robust, the quad rail had the drawback of adding weight to the lightweight AR platform.
Additionally, at times shooters with smaller hands reported discomfort with the width of the rail.
An important note, it is very common to see Picatinny rail covers, these are typically made of rubber and used to protect sections of the rail that are not in use to ensure they will not be damaged under harsh treatment.
Overall, the 1913 Picatinny rail is a durable, and reliable mounting system that secures all attachments consistently.
M-Lok Rail System
The M-Lok Rail was introduced in 2014 to directly compete with the Picatinny (Gotta love free market innovation).
M-Lok offers a sleek, smooth rail design that incorporates elongated slots where M-Lok accessories can be mounted utilizing specialized hardware.
This method removes the need for a ‘rail’ and reduces the weight and overall profile of the handguard.
Some users say M-Lok handguards provide a more natural grip, using the modern C-clamp grip.
One drawback of M-Lok rails is they are not as universal yet.
M-Lok is primarily seen on rifles, whereas Picatinny rails are seen on rifles and used on pistols for mounting lights and lasers.
Additionally, the process to attach accessories on an M-Lok requires specific hardware and can be complicated to align and securely attach accessories.
Finally, (and this might create some controversy but it is true) M-Lok does not attach accessories as securely as Picatinny, period. That is why companies don’t manufacture optics with M-Lok attachments.
Our Final Say on Picatinny vs M-Lok
To conclude, 1913 Picatinny is more universal (at the moment) and is also used for pistol mounting.
It is heavier and more robust, but that comes at the cost of weight.
M-Lok is sleek, lighter in weight, and may provide a more comfortable grip to some users.
What’s ultimately best for you depends on, well, you. If you want total universality choose Picatinny.
If weight is an issue maybe you should (hit the gym) go with an M-Lok rail.
If you shop around for AR style handguards there is something for everyone, including rails that incorporate an even mix of both.
Personally, I own both systems and I honestly cannot pick my favorite.
I have larger hands and personally find the Picatinny quad rail to offer a more comfortable grip utilizing the modern C-clamp grip.
Additionally, I find that on long days at the range, the M-Lok rifle lends itself to less fatigue (I need to hit the gym too).
Ultimately, check out both, and see which one feels best to grip.
Assess realistically what you will be using the rifle for, and if you need full Picatinny rails for mounting accessories, or if you prefer a sleeker design.