A handguard on firearms is a guard attached to the front of a firearm to grip the weapon from the front. It allows the user protection from the barrel, which may become very hot when firing. It also gives room for more attachments to the weapon itself, such as an M203 grenade launcher as well as lights, lasers, vertical foregrips, handstops and a variety of other attachments. Handguards are available in 2 different variations: Free floating and drop-in. They also use a number of mounting systems with the main ones being M-Lok, KeyMod, and Picatinny. A handguard is also a part of a sword or knife that is just above the handle. It protects the wielder's hands from an opponent's blade should it happen to slide down the blade.
Free float handguards, also referred to as "floating" handguards, have seen a rise in popularity in the recent years. They work by only attaching to the firearm at one point while the remainder of the handguard does not make contact with the barrel. This gives the impression that the handguard is "floating" above the barrel, hence the name. Free float handguards have been known to increase accuracy between.5-.75 MOA compared to their drop-in counterparts. The reason for this increase in accuracy is due to the avoidance of an issue known as barrel warping. Barrel warping occurs when the handguard makes contact with the barrel which then slightly alters the barrel's angle reducing accuracy. An instance where this would occur would be when a rifle is propped up against a surface during or when a bipod is used. Force exerted onto the handguard pushes back up against the barrel which in turn changes the barrel's angle reducing accuracy. The angle may seem insignificant, however, even a slight deviation can be magnified causing the shot to be widely off down range. Free float handguards do not suffer from barrel warping due to the fact that the handguard floats around but does not make contact with the barrel. Force exerted onto the handguard is not pushed back onto the barrel which allows for an increase in accuracy.
