Suppressed AR uppers are a hot topic nowadays, and some are integrally suppressed. But you don’t need to build an AR or an AR15 pistol with an integrally suppressed upper even if you want to reap the benefits.
In fact, as long as your barrel is threaded (and nearly all AR barrels are) you just need to know your thread size and pitch in order to get a compatible suppressor.
But let’s start with the basics.
What Is a Suppressor?
A suppressor, also more commonly known as a silencer, is a muzzle device that is designed to trap some of a barrel’s muzzle pop, thereby making the firearm shoot more quietly.
Contrary to popular belief, silencers do not actually “silence” a firearm, but they can substantially cut down on muzzle pop and overall volume, which is highly beneficial to your hearing.
The way a suppressor works is (at least in concept) actually quite simple. A suppressor consists of a metal cylinder with a bore through the middle that allows the bullet to pass through. Around the bore are a series of vanes or baffles. These trap and redirect expanding gasses so that they must bleed off some of their energy before they can escape the muzzle under lower pressure than they would if the muzzle was not equipped with a suppressor.
Since some of the energy is trapped, suppressors help to cut back on the volume of the gun’s report.
But this is not the only benefit to suppressing an AR15 pistol upper (or a rifle for that matter).
Benefits of Suppression
The most obvious benefit of suppressing an AR or an AR15 pistol upper is what has already been mentioned. It makes the gun quieter. This is a big benefit not only to your hearing, but to your rangemates. You should still use hearing protection but suppressing it still offers an advantage.
This is particularly true of AR15 pistol uppers, which are quite short, and which can be very loud, even compared to rifles.
However, there are other benefits on top of this.
One is that, since the silencer traps a lot of the hot gas at the muzzle, it severely diminishes the muzzle flash. In some cases a suppressor can even entirely eliminate the muzzle flash. This keeps your sight picture clear so you can more quickly reacquire a target.
Because the suppressor traps some of the gasses, it can substantially cut back on felt recoil as well. Perhaps not as much as a muzzle brake or a compensator would, but most shooters report that felt recoil is diminished after suppressing a platform.
This adds another benefit - cutting back on felt recoil cuts back on shooter fatigue and also minimizes muzzle jump (also called muzzle flip or rise). This makes it easier for you to keep your sights trained on target between shots, enabling faster, more accurate follow up shots.
Because of this, it is often reported that suppressors increase the accuracy of a platform. This is not entirely true. It is true that a suppressor has the potential to improve accuracy by changing barrel harmonics and cutting back on muzzle jump, but by the same token, it is also possible for a suppressor to alter barrel harmonics in a negative way that affects point of impact.
It should also be noted that since suppressors effectively extend the barrel, they can improve muzzle velocities, resulting in more power and flatter trajectories.
Are There Any Drawbacks to Suppression?
There are a few potential drawbacks to suppression; one is that they add length and weight to the platform. For an AR15 pistol upper, this will adversely affect concealability.
Moreover, a suppressor is an NFA item, so it is harder to get them than it is to get other gun parts and muzzle devices.
How Does Barrel Length Affect Performance and Suppression?
As a general rule, the longer the barrel, the more time the bullet has to accelerate and the more time propellant has to deflagrate in the chamber and the bore. Therefore, they shoot the fastest and result in the least muzzle pop.
The shorter the barrel, the more muzzle pop there will be, and the louder they will be (all else being equal). They will lose a little bit of muzzle velocity as a result. Therefore, shorter barrels (like those found with AR15 pistol uppers) tend to benefit the most from suppression.
With that said, regardless of barrel length, an AR platform stands to benefit from adding a suppressor for all of the reasons mentioned here.
Notes on Suppression
While you can benefit from suppressing any AR, regardless of barrel length or caliber, there is one important thing to keep in mind: suppressors trap a lot of gas and fouling, and increase the pressure inside the chamber and bore.
As a result, your gun will get dirtier faster and parts, like the bolt carrier group’s gas rings, will wear out sooner. As long as you are aware of this and pay a little extra attention to your gun with respect to cleaning, you should be good.
Here for an AR15 Pistol Upper?
Looking for an AR15 pistol upper for your next build? Take a look through our collection and make sure you check out our build kits while you’re here as well. Let us know if you have any questions at Sales@MCSGearup.com and we’ll be happy to help.