All about Quad Rail Uppers: The Perfect Solution for Tactical Shooters

Outfitting your trusty rifle with quad rails opens up a whole world of possibilities by letting you slap on add-ons like high-definition optics, blinding flashlights, and pinpoint lasers. These enhancements aren’t just for show – they’re all about dialing up your precision and giving your shooting skills a serious boost. Stick with us here, because we’re about to dive deep into the perks of pimping out your piece with quad rails, and we’ll toss in a handful of handy pointers for installing them the right way. Keep your eyes peeled!

What are Quad Rails?

Quad rails serve as a sort of Swiss Army knife for your firearm, equipping you with the capability to fasten a slew of additional gadgets directly onto your weapon. These versatile frameworks are fashioned in a variety of configurations and dimensions; however, they typically share a characteristic structure consisting of four linear guide rails that extend downward the length of your gun’s barrel.

No matter what type of shooter you are—whether you’re handling a shotgun, shouldering a rifle, aiming with a handgun, operating a machine gun, or rapid-firing with a sub-machinegun—quad rails are your go-to modification. Believe it or not, some sharpshooters even repurpose these rails to double as sturdy handles for their sidearms!

By far, the most acclaimed variant rocking the market is the one known as the M-LOK system, an acronym that stands for the modular locking keyhole interface. This system has taken the shooting community by storm, thanks to its blend of robustness and flexibility, as it welcomes a range of attachments without breaking a sweat.

This particular setup rolls out mounting solutions that hinge on these nifty gadgets known as T-nuts. Essentially, these little wonders latch onto pairings, binding them tightly sans the call for wrenches, spare screws, or bolt assortments. Such a streamlined approach seriously trims down the hassle, nudging the accessory fitting process into the fast lane with a marked dip in the legwork required.

How do quad rails improve performance?

Quad rail systems bestow upon your firearm the versatility to affix an array of add-ons such as illumination tools, precision pointers, and various grips, amplifying not only the visual acuity in dimly lit environments but also enhancing the stability required for true marksmanship. The presence of a dependable base essentially eliminates the uncertainty associated with an unanchored device like a handheld torch, translating to marked improvements in accuracy.

For the aesthetically driven individual, these add-ons hold the added appeal of augmenting the firearm’s visual prowess – a factor that might be just as compelling as functionality. If the allure of a more formidable-looking weapon resonates with you, then embrace that inclination with open arms! The satisfaction that follows will affirm your choice.

Sometimes, the draw towards a quad rail is less about the precision-improving aspects and more about the sheer breadth of real estate it offers for the attachment of a multitude of tactical gear. This could range from the functional – grips and bipods – to the tactically advantageous, such as forward grips and other enhancements. The expansive platform can prove to be an invaluable asset for enthusiasts keen on customizing their firearms to suit a diverse set of scenarios and personal preferences.

At MidStateFirearms here, you’ll discover an extensive selection of railed uppers that bring you options galore. We’re talking different rail lengths, gas systems, and barrel profiles, just to kick off the list. Each configuration is crafted to meet the diverse needs of shooters, whether you’re dialing in on precision or gearing up for a tactical advantage.

How to Install a Quad Rail?

Slapping a quad rail onto your rifle might strike you as a complex task, but let’s bust that myth – it’s genuinely a breeze, involving merely a handful of straightforward maneuvers!

For starters, you’ve got to liberate your firearm from the grasp of its current handguard. This part typically requires a bit of twist-and-shout with the screws or a firm, confident tug.

As soon as that old handguard has hit the bench, you’ll eye a pair of petite openings flanking the receiver – that’s your cue for the new quad rail’s grand entrance. Snag the L-shaped bracket, nudge its limbs into those slots, and fasten with screws while keeping the dance steady – don’t play shy if you need an extra pair of hands!

With both ends of the brackets anchored, it’s showtime for the new handguard. Glide that beauty over the brackets; you want them to mesh like a well-practiced handshake – firm, yet not knuckle-crushing.

Now, the grand finale: Re-attach any gizmos and gadgets that were perched atop or huddled beneath your old handguard. Their anchoring hardware’s probably playing hide and seek in the shipping box, so have a look-see and bolt those puppies on.

Give it all a once-over, double-checking for any signs of mischief before you let those rounds fly downrange.

Remember, safety isn’t just your numero uno – it’s your everything!

AR-15 Rail Systems

The choice between Picatinny, KeyMod, and M-LOK rail systems often leaves firearm enthusiasts scratching their heads, trying to navigate the nuances of outfitting their AR-15 or other firearms with the ideal rig. It’s not merely a flip of the coin; rather, it’s about delving into personal preferences that steer one towards the nuances that resonate with the user—be it the sleekness and reliability or the unique aesthetics each system flaunts.

Certainly, the tug-of-war in your wallet plays a not-so-subtle role in tipping the scales toward one rail system over another.

Facing a sea of competing options can be downright daunting. That’s why we’ve crafted an in-depth comparison, slicing through the technical jargon to present you with the lowdown on these three popular rail systems. We aim to empower you with the knowledge to pinpoint the top rail system for your setup, all the while navigating the distinctive traits that set each apart.


For decades now, the Picatinny rail has secured its spot as the go-to mounting structure for AR-15s and a myriad of other rifles out there. Conceived back in the ’80s and borrowing its name from the Picatinny Arsenal nestled in New Jersey, the Picatinny basically takes the older Weaver mount system, which W.R. Weaver Co. rolled out back in the ’30s, and kicks it up a notch. Now, if you’re lining up a Picatinny next to a Weaver, what’s going to jump out at you is that the Picatinny flaunts a more pronounced angled contour compared to what you see on the Weaver—with its lower profile and broader dovetail base. Not just that, the slots on a Picatinny rail are a tad wider and laid out with a regularity that’s hard to miss, slot to slot.

When the Picatinny first hit the scene, its primary gig was to give marksmen a solid spot to anchor their scopes onto the meatier receivers of high-caliber rifles. As times have marched on, the role of the Picatinny has spread out to support a whole arsenal of add-ons—think foregrips that give you that extra grip, night vision gizmos for those twilight escapades, tactical lights to cut through the dark, and a whole parade of others. The Picatinny rail system’s become such a staple, so woven into the fabric of firearm design, that it’s nudging out old-school iron sights and prompting designers to rework their blueprints to make room for it.

KeyMod and Picatinny Rail

Even though the Picatinny has earned a sterling reputation as a top-notch accessory rail system, you’ll find a camp of firearm enthusiasts who’d rather not deal with the extra heft it brings to the table at the forend. To counteract this predicament, one could opt for low-profile handguards that offer the flexibility to mount nifty, bite-sized Picatinny sections right where necessity dictates. Meanwhile, a portion of marksmen finds the KeyMod system to be a more suitable choice, as it dismisses the need for any Picatinny-spec adapters altogether.

The KeyMod system, birthed from a collaborative effort between VLTOR Weapon Systems out of Tucson, AZ, and Noveske Rifleworks perched in Grant Pass, OR back in 2012, takes its moniker from the keyhole pattern defining the mounting slots and its embrace of modular design principles. The KeyMod exists as an open-source, public domain blueprint, liberating manufacturers to leverage the design for crafting attachments without the obligation to cut a check to its originators.

The KeyMod system facilitates a seamless experience when securing accessories like laser mounts, optics, and vertical grips, all unencumbered by intermediary adapters. The mounting dance involves pairing the lugs on the accessory with the circular segment of the KeyMod’s keyholes, nudging the accessory forward, then securing it with a firm twist of the fastening screws.

When it comes down to choosing between the heftier Picatinny and the KeyMod, for many firearms holders, it’s the weight difference that tips the scales. The KeyMod, free from the need for extra adapter paraphernalia, offers a featherlight alternative, enhancing firearm maneuverability, control, and portability. Beyond weight, the KeyMod also edges out with its user-friendly contours, spared from the biting edges that brand Picatinny quad rails, offering a smooth, glove-free handling experience.

For those who’ve made peace with the added weight and more robust profile of the Picatinny, it’s nothing short of a solid pick. It’s the epitome of user-friendliness in accessory mounting, assuring fitment for just about any gadget you might fancy, sans the nuisance of shelling out for sundry parts or complications.

Fastening your choice trinkets to a Picatinny rail? Piece of cake. Clamp the addition onto any open berth and cinch it down with the nifty thumbscrew, a quick-detach lever, or the simplicity of a bolt. You also have the freedom to introduce the accessory from the rail’s business end and lock it down precisely where it feels right.

M-LOK As an Alternative to the KeyMod

Back in 2014, the folks over at Magpul Industries, hailing from the vibrant city of Austin, Texas, pulled the covers off a new twist to the KeyMod system. This innovation was christened M-Lok, short for Modular Lock, and it was crafted with the intent to mesh seamlessly with polymer-based add-ons.

This M-LOK innovation can be seen as the next chapter in the story of their Magpul Original Equipment (MOE) mounting narrative, adopting the foundational KeyMod concept of using negative space to its advantage. Much like its predecessor, the M-LOK system boasts attributes such as a slender outline, feathery feel, and a modular railing architecture that lets users customize to their liking.

Drilling down into the specifics, though, here’s where the M-LOK and KeyMod part ways – it’s all about their respective approaches to hanging rails and gadgets up. Ditching KeyMod’s signature keyhole pattern, the M-LOK opts for a set of streamlined, uniform slots. Whichever way you flip them, M-LOK-compatible accouterments are set to go, thanks to their savvy t-shaped, go-either-way attachment nubs. This nifty feature primes M-LOK for an edge in the M-LOK versus KeyMod debate, since KeyMod gear has got to stick with rear-end mounting only.

Now, if you pit M-LOK against the seasoned Picatinny rails, the former might just win you over with comfort. M-LOK’s beveled notches are kinder to the touch; they won’t bite or scratch, offering up a handguard that’s a breeze to grip.

But here’s the kicker: M-LOK isn’t playing the open-source game like KeyMod. Magpul plays it differently, extending a hand with their gratis licensing, provided manufacturers get their nods in front of time. This shrewd move by Magpul means consistency is king; every gadget flaunting the M-LOK badge is guaranteed to match up to the high standards set by the original, paving the way for hassle-free accessory swapping.

What’s the Best Choice?

Pinning down the superior pick for an AR-15 rail system? That’s about as straightforward as a winding back-country road. It’s your call, your game. While you’re mulling over the options for your rail systems, chew over not just the aesthetics that catch your eye, but also the heft you’re prepared to pack, and the chunk of change you’re willing to part with. These factors should steer you towards a decision that feels just right.

Much like the fluctuating tides of any mercantile landscape, it’s the end-user who’ll eventually tip the scales, influencing which AR-15 rail systems stand the test of time and market pressures.