The AR15 rifle platform has went through many stages of upgrades to make it even more reliable, modular and adaptive.
One of the most common AR upgrade accessories is the handguard system, and in this informational guide, we gonna talk about the difference between a free float and a drop in handguard.
They all serve the same purpose for mounting accessories and provide a spot for the shooter to grip the rifle, but they mount differently on the rifle receiver and the their reliability differ.
How They Differ?
Drop In Handguard - Two Piece
Drop in handguard is the old school handguard system that requires the top and the bottom piece to held in place using a delta-ring with a spring load mechanism.
For the most part this system is commonly found on AR15s with the delta ring design on the upper receiver. Some are made with polymer like the MAGPUL MOE handguard, and most are mil-spec picatinny quad rails made with 6061 T6 aluminum.
So why use this? Drop-in hand guards are easy to remove and replace. All you do is to push the delta-ring forward hence releasing tension on the guard.
Drop in handguards are also very inexpensive and lightweight.
What's the down side? Drop in handguards are inherently wobbly and inaccurate for mounting precision devices such as aiming lasers. In addition, the frontal handguard retainer acts as a fixed spot that exerts force on the barrel, which interrupts the barrel harmonics when a round is fired creates accuracy issue for
Free Float - Doesn't Interrupt Barrel Harmonics
Free float handguards are the most modern design up to date. Most of them are precision CNC machined from one block of aluminum, which gives the rail system plenty of creative designs and modular features to accept accessories to mount grips, lights and lasers.
The handguard is directly attached to the rifle’s upper-receiver via the barrel nut and no other part of the handguard touches the barrel at all.
So why use this one? Since the free float handguard does not touch the barrel, it preserves the barrel harmonics when rounds are fired for better accuracy. Apart from this, free float handguards can be as short as they want or as long as they want without interfering with the gas block clearance. In addition, most complete AR upper receivers ship with free float rail system.
What's the down side? Most free float handguards require specific barrel nut systems to secure the installation.
However, most the barrel nuts that come with the rails don't provide stiff cantilever mounting platform that helps to increase the surface contact where the rail interfaces with the receiver and creates a platform that can be trusted to be straight and true the entire length of the free float rail.
(So far we like the Geissele Automatics' free float rail handguards that offer the toughest mounting barrel nut system)
Which One Is Better?
Both systems work, and it all depends on what the users want. For serious AR15 owners, going with a free float rail handguard system is the better way to go for increased durability, improved barrel performance, improved heat resistance, added modularity and enhanced aesthetics.
For casual AR owners, a standard AR15 with drop in quad rail works just fine and the the rifle can always be upgraded later to a free float rail system in the future.
Both rail systems have M LOK, KeyMod & 1913 Picatinny available. If you want to learn more about MLOK vs KeyMod, please click here.
Show Me What Are The Cool Rail Handguards
We have created a handguard shopping guide for the AR15, which you can check it out here.