Building Your Perfect 3-Gun Rifle: Part 4

(Madalyn Stewart’s 3-Gun Rifle)

Part 4: Lower Receiver Component Selection

While upper receiver components are essential to rifle performance and accuracy, lower parts also play a vital role in ensuring consistent function and precise manipulation of the AR-15 platform. Trigger interface, control configuration, furniture design, and buffer construction can all vary significantly based on individual user preference.

Here is a brief overview of what Criterion Barrels sponsored shooters prefer to run on their personal 3-Gun rifle builds:

ADM Billet Lower

(Pictured is a billet AR-15 lower receiver featuring ambidextrous controls from American Defense MFG. – Photo credit American Defense MFG)

Lower Receiver:

Niki Clevenger: I used to run mil-spec forged lowers on my 3-Gun builds but now I use a billet lower receivers from American Defense MFG.

Heath Clevenger: ADM offers a premium CNC machined lower receiver with built-in ambidextrous controls. Next to them I would choose a good mil-spec forged receiver. I would stay away from blemished receivers. Sometimes the area of the receiver that is out of spec will have an effect on the function of the rifle.

Thomas & Madalyn Stewart: As I said in the upper receiver article, the biggest concern here is to have in-spec items that fit and match other parts used. The upper and lower need to have a tight fit to eliminate any movement between them at the pivot points. I have not noticed any major performance differencs between forged and billet sets, but the published manufacturer specifications seem to indicate that billet performs better. I currently use ADM ambidextrous receiver sets. This choice was based on the quality of the material and machining, as well as the control system they use for bolt lock and magazine release.

Sean Dexter: When it comes to lower receivers, NEMO and Midwest Industries consistently offer high quality parts, so I generally tend to go with them.

Hiperfire Hipertoouch 24

(Pictured is a Hiperfire Hipertouch 24. Photo Credit: Little Crow Gunworks)


Niki: I prefer a flat trigger. I have found that my finger tends to slip on a curved or rounded trigger, not sure if it’s nerves, sweat, or just my smooth skin. I like a flat, crisp trigger that doesn’t have a lot of take-up or slack. When I am ready to fire my rifle I don’t want too much time to think about it more than I already have, or have the motion from pulling a trigger with substantial take-up move my sights off target. A trigger with a consistent trigger pull and a quick reset really catches my attention when I am trying different trigger designs.

I am currently running a Hiperfire TH24 which is similar to the 24C, the only difference being that it’s nickel coated. The TH24 and 24C both come with a shoe on a flat trigger. I feel as though the shoe really helps keep my finger in place, preventing it from slipping too far past the trigger while simultaneously making me place enough finger on the shoe in order to effectively engage the trigger.

Heath: I currently run a Timney flat single stage trigger. I have run some great Hiperfire triggers and triggers from CMC as well. As long as it breaks around 3 lbs and doesn’t have a lot of travel, I like it. I do like the very positive reset on the Timney trigger quite a bit.

Thomas & Madalyn: A good trigger can be one of the biggest add-ons available. It can help improve the accuracy and efficiency of your rifle. A 3-Gun rifle trigger has two very different requirements that it will be judged by. The first is the break. Just like any other trigger, to be accurate it will need a clean, crisp break without pre-creep or excessive overtravel.

The second aspect that is more unique to 3-Gun is the desire to have the shortest reset possible. The shorter reset aids in high speed trigger manipulation while trying to put two shots on paper as fast as possible, allowing the shooter to transition to the next target. To meet both of these requirements, single stage triggers are typically the only models found in 3-Gun rifles.

There are many companies that produce quality triggers with slight differences in pull feel and trigger shape. From the many quality triggers out there, it is a personal preference on what each shooter wants their trigger pull to feel like, so it is best to try several before buying one.

Sean: I use a CMC single stage 3.5 lb trigger in each of my 3-Gun rifles.


(Adjustable stocks such as this B5 Systems SOPMOD stock allow the user to adjust length of pull on the fly)


Sean: VLTOR stocks look and feel great. They make stock models for a variety of shooter preferences.

Niki: Before the Armalite 3-Man 3-Gun match in 2015 I ran an adjustable stock on my rifle. I marked on it where it needed to be set up for shooting close run-and-gun stages, and marked where I neded it to be set for shooting long range. I ran into a malfunction that required me to slam my stock onto the ground, which unfortunately broke the adjustable stock. Since then I have started using fixed stocks. I may switch back to an adjustable stock for this season.

Heath: I am currently running the Magpul adjustable stock that came standard with my ADM rifle. I’m not very picky so long as it’s adjustable. I like to set it up for shooting and standing one or two notches from full extension, and bump it out to full extension for prone work. That generally provides me with optimum eye relief.

Thomas & Madalyn: Stock length and type is dependent on a person’s shooting style. I normally shoot with a collapsible carbine stock fully closed. This allows me to shoot with my shoulders nearly square to the targete, and allows my nose to touch the charging handle with consistent ee relief. If using an adjustable stock it needs to be solid without wobble between the stock and (buffer) tube. To help eliminate this wobble I will wrap electrical tape around the buffer tube.

Niki Clevenger RIfle Sling

(Niki normally runs a simple two point sling with her 3-Gun rifle setup)

Rifle Sling:

Sean: I use a Botach Tactical 2-point padded sling because they are very affordable and allow me a quick release option in order to get my rifle or shotgun into action.

Niki: My sling attaches to the stock of my rifle through a loop that is already built into the stock (thank you Magpul!). I added another attachment point to the handguard, connecting the other end of the sling to a carabiner that then clips to that attachment point on the handguard. This allows me to easily unclip the sling from the front of my rifle as I am pulling it into position to shoot. The great thing about needing a sling for 3-Gun matches is that there are no strict guidelines on how your rifle has to be slung, so I normally sling my rifle in whatever way keeps it from falling off or creating a tripping hazard.

Heath: I prefer the Magpul MS3 due to the ease of unhooking it from the front of the rifle and multiple methods of switching it out from a 2-point configuration to a single point sling (all in one package). It’s also easy to swap from one rifle to the other.

Thomas & Madalyn: For 3-Gun I prefer to run a two point sling on the port side of my rifle. My preference is the Blue Force Gear Vickers Combat Application Sling (VCAS). This sling allows me to adjust the length with an easy to use pull tab and does not have a loose tail to get tangled on or around things.

Depending on how much movement and what guns will be used prior to the rifle dictates if I sling in front with the muzzle down, or on my back with the muzzle pointed upward. If I’m only shooting pistol before rifle I will normally sling in front to allow bringing the rifle up to a shooting position quicker. If there are shotgun reloads or more movement around obstacles I will sling on my back and snug the sling tight.

MAgpul Pmag

(Magpul Pmags are nearly universally available through any number of firearm retailers)


Niki: For competition shooting you need various different magazine capacities. Twenty round magazines are useful for shooting off rooftops or angled surfaces. Coupling magazines allows for a wider base similar to a monopod when shooting from the prone, also allowing for quick reloads. It never hurts to have a magazine that can hold 40+ rounds for shooting exclusively rifle stages. Reloading can cost a shooter plenty of time if you don’t seat the magazine correctly. Nothing is more heartbreaking than reloading, firing one shot, and hearing your loaded magazine hit the ground. The less you need to reload the better!

Heath: My primary magazines for competition are Magpul Pmags. I usually carry an aluminum backup magazine as well. I normally don’t leave the Magpul magazines loaded and sitting around. I prefer to unload them at the end of every match and reload them at the beginning of the next match. I have read that the lips on the Magpul magazines fail over time, but that an old fashioned aluminum or steel magazine tend to last a bit longer. Both Magpul and metal magazines are disposable commodities, but I find that I replace my Pmags a bit more frequently.

Thomas & Madalyn: The biggest mistake I see with magazines is a tendency of shooters to fail to look at them as an expendable item. Magazines have a lifespan much shorter than a rifle, but people frequently use them year after year while upgrading other equipment. Many rifle malfunctions are caused by magazine issues that could be resolved by a $15.00 replacement.

My preference in magazines leans toward Lancer L5 Advanced Warfighter Magazines in 20 and 30 round configurations. I also use Magpul 40 round magazines with five round extensions for longer stages. Another item to use with magazines are couplers. Much like Niki, I rarely use them for reloads, but instead as a stablization aid for long range prone positions. The larger (wider) footprint helps along with the stablizing weight of two magazines.

MAgpul BAD Lever

(The Magpul BAD Lever allows for ambidextrous bolt manipulation with standard AR-15 lower receivers)


Thomas & Madalyn: I’m right handed but still prefer to have ambidextrous controls for the charging handle, bolt, and magazine release. This gives you more options in weapon manipulation when in odd shooting positions. I choose not to attach the second side of the ambidextrous safety as it interferes with my trigger finger index point. I have started to use the AXTS Talon 45 Degree safety, as the function of that particular safety is very smooth and easy to manipulate.

Sean: I normally run a fairly stock setup in this regard. The traditional AR-15 controls work for me.

Niki: The BAD (Battery Assist Device) Lever is another quality product from Magpul. It allows you to easily lock the bolt back by pressing up on the lever and pulling the charging handle with your offhand, without having to move your dominant hand from its position. It also allows for a quick bolt release if your rifle runs empty and you need to reload a fresh magazine. American Defense MFG offers integrated ambidextrous controls already built into the receiver, so in that situation the BAD Lever is unnecessary.

Heath: I really like how the ADM rifle comes from the factory.It has a 60 degree ambidextrous safety, enlarged ambi charging handle, ambi bolt stock/release, and ambi magazine controls. This allows the shooter to maintain the same grip on the rifle regardless of the function that needs to be performed while holding the rifle. If you are not using a receiver set up with ambidextrous controls, I would definitely recommend using the BAD Lever to allow you to keep a firing grip while clearing the rifle.


While the rifle builds showcased in this four part article range widely in component selection and build strategy, they reflect an extremely small selection when compared to the plethora of options currently available for the 3-Gun rifle platform. It is our hope that this analysis will provide both new and veteran shooters with alternate viewpoints when considering part selection during future rifle build projects.

Part 1: Introduction to the Perfect 3-Gun Build
Part 2: Functions, Classifications, and Build Strategies of the Ideal 3-Gun Rifle.
Part 3: Upper Receiver Component Selection.
Part 4: Lower Receiver Component Selection.

Criterion Barrels always welcomes feedback and input from shooters using our products. If you would like to share details regarding your ideal 3-gun rifle build (that includes your preferred Criterion barrel model), feel free to send us a list of build specs and a photo of the rifle, submitting your response to [email protected]

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