If you want to get full use of an AR-style rifle, engaging it with different uppers is so natural. While you could buy a dedicated rifle and use it for one special purpose, AR users can swap out a tactical carbine upper with a big-bore-caliber upper suitable for hog hunting. Think about it. By removing just two parts—the takedown pin and the pivot pin—you can completely transform an AR into another rifle. It was built to be modular and adaptable.

The M16 entered service with the United States military in 1962 and has become one of our country’s longest-serving battle rifles. Over the decades, the AR platform has evolved with each successive model number, with each offering improvements over the previous model. Today, civilian variants of the M16 rifle and M4 Carbine can be found in deer camps, in homes for personal defense and on rifle ranges competing in various matches.

Tactical AR Add-Ons

ar rifle gl-mag buttstock
An innovative add-on, the adjustable GL-MAG buttstock from FAB Defense is designed to hold a spare AR magazine.

The trick with swapping uppers on an AR is the caliber. A caliber is made to do a specific job, but sometimes it needs to perform multiple jobs. Caliber diameters may change according to the scenario, but the length of the cartridge must be able to work within the dimensions of the magazine well on the AR’s lower receiver. That means the overall cartridge length is 2.25 inches no matter the bullet diameter.

A lower receiver that is compatible with various uppers should also be as adaptable as the uppers. First, consider the stock.

A sturdy, adjustable stock that won’t snag on anything is key. The ability to adjust the stock’s length of pull makes a gun “user-friendly” for different-sized shooters. When your significant other pulls the AR to her shoulder, for example, you want to make sure it fits her petite size. Also, when you are training in warm weather and wearing a T-shirt, you might fully extend the stock. While hunting in cold weather, you might collapse the stock a couple of notches to accommodate a thick coat.

The quick adjustability of the stock is a great feature and benefit of the AR platform. Companies like Magpul, Hogue, Vltor, FAB Defense and others offer stocks with multiple adjustment positions. Some, like the Magpul ACS, also have small compartments to store optic batteries, and others have built-in magazine carriers like the FAB Defense GL-MAG stock.

ar rifle bravo company grip
Bravo Company’s Gunfighter pistol grips have internal storage compartments as well as high beavertails for better ergonomics.

Next, consider the trigger. The two-stage, mil-spec triggers are fine and perform without question, but a crisp trigger can instantly help make you a better shooter. The Geissele SSA-E trigger has a reduced first-stage take-up and a crisp second-stage pull. Timney triggers are also famous for being smooth and crisp with light pull weights.

The third item to address is the grip. The standard A2-style grip works well, but there are better, more comfortable options, like the BCM Gunfighter Mod 3 grip from Bravo Company USA. This grip has a reduced angle for improved ergonomics and better trigger control. It is also wide and has an extended forward tang that closes the gap between the triggerguard and pistol grip, and the backstrap has its own high-rise beavertail. Another model, the TangoDown Flip Grip, can be adjusted for a 24-degree rake or positioned vertically.

The grip angle is important depending on your shooting position. The Stark AR-15 Sling Grip features an ambidextrous sling mount for a single-point sling. Of course, as with all your tactical equipment, try out various designs and use what feels best. Investing in a stock, grip, and trigger eases upper transitions and makes a more adaptable AR.

Close-Quarters Battle

ar rifle wilson combat trim handguards
Wilson Combat’s TRIM handguards are easy to customize because they’re drilled and tapped on the sides and bottom for the easy addition of Picatinny rails.

For personal defense, a civilian version of the M4 Carbine is a good choice. Uppers equipped with red-dot or reflex sights are excellent setups for home defense and training. In a pinch, plain iron sights also work just as fine. The 5.56mm NATO/.223 Remington is an excellent self-defense round. And when things go bump in the night, reaching for an AR with a 16-inch barrel and a 30-round magazine can be comforting.

A fine example of a defensive AR carbine is Wilson Combat’s Recon Tactical. Wilson Combat goes to great lengths to ensure its rifles perform every time, no matter what the conditions are. In fact, Wilson Combat manufactures uppers in a variety of calibers to meet every operator’s needs. The Recon Tactical lower is an excellent foundation for an AR. It starts with a rubber Ergo pistol grip, a Rogers Super-Stoc and Wilson Combat’s own Tactical Trigger Unit, which is a single-stage trigger with a 4-pound pull—a weight that works well with or without gloves.

The Recon Tactical also has a 16-inch, match-grade barrel. The muzzle is threaded and comes equipped with an Accu-Tac flash suppressor. With the stock fully collapsed, the 16-inch barrel does not pose a liability when maneuvering down hallways, entering rooms with narrow doors or easing around a corner. In this defense/training mode, the carbine is very practical.

The handguard on the Recon Tactical is a Wilson Combat TRIM, and as the name implies, it’s narrow in hand. The top of the upper is all rail, too, and that’s where a reflex sight can be added for this defensive setup.

On The Hunt

ar rifle 6.8 SPC upper
Consider getting a 6.8 SPC upper, as this chambering is more powerful than the 5.56mm NATO/.223 Remington, yet it’ll still work with a 5.56mm-sized lower receiver and magazines.

A second dedicated upper transforms the AR from a home-defense weapon to a deer rifle. In the same way that military rifles of the past, like the Springfield Trapdoor from the late 1880s and the bolt-action Springfield M1903 from the early 20th century, were used by civilians for hunting, so too is the AR.

An upper chambered for the 6.8 SPC is a good choice for deer. The round was developed to improve the lack of knockdown power experienced with the the 5.56mm NATO/.223 Remington. It fits within the envelope of the typcial AR lower and kills deer. Wilson Combat offers a complete upper assembly in 6.8 SPC with a 16-inch, fluted barrel that has a 1-in-11-inch twist rate. This twist rate works well with bullet weights in the 110-grain range. A 6.8 SPC cartridge with a 110-grain bullet has a speed of about 2,500 feet per second and muzzle energy of 1,525 foot-pounds. Mount a scope and your second upper is ready for deer.

Load a third upper for bear or pigs—big, wild pigs. The Wilson Combat complete upper in .458 SOCOM is a thumper, pushing a 250-grain bullet at about 2,150 fps with muzzle energy of 3,478 foot-pounds. That’s plenty of power to drop a pig like a sack of grain. The .458 SOCOM cartridge will work in a 5.56mm NATO/.223 Remington magazine, too, though the total capacity will be less since the .458 SOCOM cartridges are fat compared to the slender 5.56mm/.223 rounds.

With these examples in mind, it’s clear that swapping out uppers means you can dedicate an upper for a specific role and use your AR for three kinds of engagements. It’s just a matter of planning and finding the right gear.

For More Information

Bravo Company USA

FAB Defense

Geissele Automatics



Stark Equipment

Wilson Combat

This article was originally published in “The Complete Book of Guns” 2018 #200. To get a copy, visit

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