If you buy an assembled upper instead of a stripped upper and components, the assembly is going to come with a handguard.
Which means, much like you’ll have to think about bolt carrier group coating and barrel length, you will also have to consider the handguard style.
The handguard you choose will impact not only what accessories will be compatible with it, but also the ergonomics of the finished AR style rifle.
So, with that said, here are the major types of AR handguards and rail systems, along with some notes on their strengths and weaknesses.
Picatinny Handguards and Quad Rail Handguards
Picatinny handguards, commonly referred to as Pic or Pic rail handguards, are the classic option. Around 30 years old, the “Pic” rail, as it has come to be known, was developed at Picatinny Arsenal in New Jersey and consists of a series of slots and grooves on top of which shooting accessories, like optics, can be mounted.
Because of its age and ubiquity, Picatinny handguards are among the most commonly encountered, and moreover, there is a larger number of shooting accessories compatible with them than with other styles of AR handguards.
Pic handguards are commonly made as “quad rail” handguards, in which configuration there are 4 sections of Picatinny rail around the handguard - on the top, bottom, and on both sides, hence the name.
They are also relatively affordable, and offer a sure grip. However, they are fairly heavy and some users find gripping a Picatinny handguard without gloves to be quite uncomfortable.
About Pic Rail Covers
Because of the aforementioned note, that some users find Picatinny rails to be uncomfortable, many users cover up the unused sections of the handguard’s rails with Pic rail covers, which cover up the slots and make the rail more comfortable to hold.
While this improves comfort, it also adds even more weight to the Picatinny handguard and also complicates heat dissipation.
M-LOK Handguards
A popular alternative to Picatinny rail systems is the M-LOK rail system, which is much newer than the former.
M-LOK handguards consist of a series of lozenge-shaped slots that accept compatible accessories. Though the number of M-LOK compatible accessories is lower than those for Pic rails, it is growing.
Moreover, M-LOK handguards offer numerous advantages over Pic rail systems. M-LOK handguards are lighter in weight, more comfortable to hold (eliminating the need for Pic rail covers) and offer better heat dissipation for the barrel, too.
KeyMod Handguards
KeyMod handguards are roughly as old as M-LOK handguards, which means they are also newer than Pic rail systems. As a result, there are fewer compatible KeyMod accessories - though, again, the number grows every year.
Like M-LOK handguards, KeyMod handguards consist of a series of slots - though in the KeyMod system, they are more pear-shaped. Otherwise, like the M-LOK system, they are lighter and more comfortable than Picatinny handguards.
Another thing worth mentioning is that both M-LOK and KeyMod handguards, despite the fact that they are slightly limited in what accessories they can accept, are very easy to use.
Free Float Handguards
In the world of rifle barrel bedding, there is a term known as “free-floating.” In conventional rifles, a barrel can be said to be “free floated” if the stock does not make contact with the barrel.
It follows then that free float handguards also do not make contact with the rifle’s barrel. They bypass the barrel entirely and attach to the upper receiver via the barrel nut.
Regardless of which rail system appeals to you, if you are looking for an assembled upper, it is strongly advisable to choose one that has a free float handguard.
This is because, by eliminating handguard and barrel contact, it can be further assured that no undue or unwanted forces are imparted on the barrel, at least from the handguard.
This eliminates pressure and torque on the barrel, and can optimize barrel harmonics, which is a long way of saying that in order to deliver the best possible accuracy, a barrel must be free-floated.
For plinking and close-range shooting, it’s not a big deal. But if you shoot at extended ranges with your AR (or at least if you plan to) the barrel should be free-floated.
Shop Assembled Uppers Here
Regardless of whether you want a Pic, M-LOK or KeyMod handguard, or if you intend to go with one that is free-floated or not, we carry a wide range of options in our assembled uppers here.
Shop our full collection of assembled uppers, which includes models with free-floated handguards, including Pic, KeyMod and M-LOK uppers. We also carry a variety of AR15 pistol uppers and short uppers that you can use for SBR builds.
For more information on the specifications of any of our uppers, get in touch with us at Sales@MCSGearup.com.