If you’re really getting into building rifles, then there are a lot of things for you to consider. Barrel length, steel alloy, and barrel coating. Bolt carrier group coatings. Whether or not you want to build with a stripped or an assembled upper. Whether or not you want a forged or billet lower. What sort of muzzle device or trigger group to install.
And so on and so forth.
One other thing you will want to put under the microscope is the AR handguard, because, in fact, this part actually can impact how the rifle shoots (and how accurate it can be after tuning) and not just how to mount accessories.
So let’s get into a trend that’s growing among AR builders, which is the use of free-float handguards.
Why You Might Want to Build with a Free Float Handguard for Your AR
You might be familiar with the concept of free-floating a barrel with respect to precision rifles, because that’s been commonplace in rifle design for a while now. But, let’s talk about what a free float handguard actually is.
At its core, it means fundamentally the same thing as it does elsewhere - a free float handguard is one that does not contact the barrel - just the same way that the stock of a bolt-action rifle with a free-floated barrel does not contact it.
The concept here is to eliminate contact between the barrel and all other parts of the gun. The only part the barrel contacts is the upper receiver and it is secured through the barrel nut. That part is unavoidable, but you can eliminate contact with the handguard.
The theory here, which is substantiated through physical extrapolation as well as through testing, is to optimize accuracy.
You see, when you fire a rifle barrel, it vibrates a lot. This is what we call barrel harmonics, and when the muzzle of the barrel is vibrating such that it is out of alignment with the centerline of the bore, we call this barrel whip.
Barrel whip results in very minor aberrations in accuracy, which, while they usually aren’t that much of a concern at intermediate ranges, can result in less-than-desirable groups at extended ranges. So for precision rifle shooters - such as those who choose AR platforms for long-range shooting, barrel whip is a bad thing.
It is impossible to eliminate barrel harmonics, but what you can do is eliminate factors that contribute to less-than ideal harmonics - such as barrel whip.
Two of the things that magnify barrel whip are muzzle devices that are too heavy, and points of contact between the rifle barrel and the stock or the handguard. These restrictions place torque on the rifle barrel, alter its natural oscillation and prevent it from vibrating freely.
In a nutshell, a free float handguard is the choice you’ll want to make for your rifle if pinpoint precision is a concern for you. If you hunt or compete at intermediate ranges or intend to use the rifle for defensive applications, it might not be worth it - but if you intend to shoot at great distances, a free float AR handguard is the prime choice.
Now, here’s another thing. For other AR handguards that do contact the barrel, any instances of negative effect on barrel whip can be made worse by mounting accessories, as these will add mass and therefore pressure to the barrel where they are mounted.
However, if you use a free float handguard, you can write off this concern because it won’t matter how weight is distributed on the handguard, whereas it would make a difference if the handguard was not free-floated.
Let’s Not Mince Words: Free Float Handguards with Respect to Mounting Systems
One disclaimer we have to publish is that calling a handguard a “free float” AR handguard has nothing to do with how the accessories are mounted. Rather it refers to how the handguard itself mounts to the platform and that it does not contact the barrel.
It should be made clear that free float handguards could theoretically use any type of rail system, which means that Picatinny, KeyMod, and M-LOK rail systems can all be integrated with free float AR handguards.
In fact, you could even have a tropical style handguard that could be theoretically free floated, though that would not have any mounting points.
The point is, if you’re interested in a solution that will uphold the highest standards of accuracy for your rifle build, a free float handguard won’t hold you back. You can get it with any rail system you want.
Shop AR Handguards
Here for a new AR handguard for your next build, and want a free float configuration? Shop our collection of KeyMod and M-LOK rail systems here to find what you need and if you have questions get in touch with us at Sales@MCSGearup.com for more information.