Intro to AE Suppressors

So you are wanting to buy an Allen Engineering suppressor but don’t know where to start? There is a lot to learn about the OPS INC/Allen Engineering ecosystem, from its long (and sometimes confusing) history to technical knowledge. 

Let’s start at the beginning. OPS INC™ was founded by Phil Seberger in the 1980s. He would go on to design a series of suppressors that would be adopted by various branches of the U.S. Military and law enforcement. Phil brought on Ron Allen in the 1990s to help with manufacturing and they remained partners until OPS INC shut down in the 2010s. After Phil’s death, Ron continued making the same suppressors under his company Allen Engineering with new model nomenclature. I will often stay OPS/AE because while they are separate companies, the products produced have remained the same.

Knowing how to use an Allen Engineering suppressor begins with understanding how it works. OPS/AE suppressors utilize a reflex design, which means they mount over the barrel. This helps increase internal volume without increasing added length. For example, the AEM5 is 8.8″ long but only adds 6.3″ to the end of your barrel. That is a similar added length as a Surefire® RC2, but you are getting the performance of a longer suppressor. 

The reflex design is primarily due however to AE suppressors using a 2-point mounting system. The first point is either the muzzle threads on the barrel or a muzzle device which the suppressor will thread itself onto.

The second point is the taper. The taper is how the OPS INC/ Allen Engineering suppressor aligns and secures itself. The matching taper locks the suppressor in place as well as realigns the suppressor to the same point every time. This gives you unmatched repeatability when you remove and reinstall the suppressor. The two points of contact also don’t rely on the tiny 90 degree shoulder that other suppressors do which gives exceptional rigidity critical in precision rifle setups. There are several different ways to provide the taper for the suppressor. Direct cut into the barrel, or with an adapter collar of some type.

Taper Collars: This is the traditional collar that most people are familiar with. It is pushed up against a step in the barrel and secured with a set screw. While there are only a couple standard types like the MOD 0 and MOD 1 SPR collars, there have been many different versions made to adapt to various unique barrels and suppressor situations. You can read more about the various types of collars available here.

3-Piece Collars: This collar contains an inner tapered sleeve that is fitted to the barrel and a donut that clamps over the sleeve to retain it. This collar is reminiscent of early mounts of the 90s and are typically used on ARs with front sight blocks, most commonly with “Gordon Clone” builds. Its comes in a long and short version depending on what suppressor you want to use. 

Gas Block Collars: This is when the taper is added onto a gas block so it can act as a collar. Although this option isn’t common, it helps reduce the AE mounting system to its shortest possible configuration. There are several standard barrel lengths that these will work with, but often a gunsmith will need to cut a barrel to a custom length to work. This option does offer a “short dwell” option which can be excellent for dedicated suppressor setups. 

Direct Profile: This is when the required taper is directly profiled on the barrel. This only works on barrels that have a .92″ minimum diameter which means this is only possibly on heavy barrels. This is the only option which does not require a collar because the taper is cut directly into the barrel.

Single Point: This option is the catch-all for odd barrel situations. It provides the necessary taper for the suppressor, however they typically free float and are reliant on the tiny 90 degree shoulder like a standard muzzle device so they don’t proved the same level of rigidity as a 2-point system does. OPS INC made a version many years ago for some unique situations and we have brought it back as the BYOB (Bring Your Own Brake). Another option would be the OCL OTB device. 

It is also important to know that various AE suppressors require different mounting lengths. The mounting length is how far the suppressor mounts over the barrel and is measured from the muzzle of the barrel to the taper on the collar. Most AE suppressors are mounted onto a muzzle device, but there are some models that are direct thread. The brake mounted suppressors are broken up into two mounting styles: A-Mount and B-Mount. The direct thread models typically have a mounting length unique to that suppressor. 

So, why do you need to know about mounting lengths? Well, if you wanted to mount an AEM5 which has a 2.5″ mounting length, but you only have 2.25″ of exposed barrel then you might want to consider a shorter mounting length.

Below you will see the mounting length requirements across the different mounting styles. You will also see which mounting styles certain AE suppressors use. 

Unfortunately mounting a collar on your barrel isn’t always a plug and play situation. So when you ask “which collar will fit on my barrel?” there is no easy answer. There are many different barrel manufacturers who make a wide variety of barrel styles/profiles, all with ranging tolerances. 

There are some barrel profiles that will easily accept a collar, such as the MK12  profile. Looking for a barrel that lists compatibility with OPS/AE mounts is a good start, however a few companies have made some mistakes over the years. We are expanding our selection of SPR collars to fit popular barrels such as Daniel Defense, Criterion, and others that either have the wrong dimensions or unique profiles.

But what if you have a barrel that doesn’t accept a premade collar? A competent gunsmith with a lathe should be able to do the job. Here are a few gunsmiths we trust to work on AE projects.