Why Lightweight Carbines Are a Game Changer

Subtracting weight from your carbine can simply be a matter of making smart choices in your gear selection.

posted on November 26, 2021

Technology and demand are driving a light-rifle trend that shows no signs of slowing down. Purpose-built, flyweight guns are a dream to carry and shoot, but the additional machining, exotic materials and manufacturing methods that can bring something like an AR rifle down to 4.5 pounds make it expensive. Fortunately, there are cost-effective options for cutting weight on existing rifles, too. This work can be divided into gunsmith-specific tasks which require special tooling and machining skills, and those components which require nothing more elaborate than a screwdriver to install. The latter category is the focus of our efforts here.

A sizeable chunk of the following component options is AR-specific, but there are also varying degrees of lightweight, retrofit parts for other rifle platforms, including AKs, M1As, FALs and Mini-14s. Options will also be on the table for any long arms that use AR-style stocks, grips and rail-mounted ancillary devices. Speaking of stocks, the included tables show how ounces can be shed in both the collapsible and fixed categories. As with the items shown in other tables, these are just a few samples shown in comparison to standard-component weights. All data comes from the author’s measurements or manufacturers’ published specifications.

Assuming that you ordered the correct stock size (mil-spec or commercial) for your receiver extension, collapsible-stock changes can usually be made in just a few seconds. As in the case of the ATI Tactilite stock, if a rubber buttpad is removable, additional ounces may be shaved. Fixed-stock changes call for some form of screwdriver, and the lightest, easy-to-install models typically form a small shouldering piece, mounted to the back of the receiver extension.

Another easily changed part is the AR-style pistol grip. With nothing more than a screwdriver, an ounce or two can easily be shed. Just be careful to reinstall any detent pins and springs held in place by the grip the same way that they came out.

Swapping bolt-carrier groups (BCGs) is a simple way to drop more ounces. But, with lightened steel carriers just shy of $200 and titanium bolt-carrier groups starting close to $300, this is an expensive part of the rifle diet. Since the bolt carrier is the lightened part, I purchase them stripped for retrofit work when possible. This allows use of an existing, headspaced bolt and other parts. If you go for the full BCG, be sure the new bolt gets checked for proper headspace in your barrel before use.

While you have your BCG pulled apart, you can cut the weight of your firing pin nearly in half by switching from stainless steel to titanium. I have been using Ti firing pins in small- and large-frame AR firearms for around three years without any breakage or wear. The traditional AR magazine catch is simple to change, normally requiring only a tool or cartridge tip to push the button in far enough that the catch may be unscrewed as it protrudes from the left side of the lower receiver. The ounce shedding continues with the grip screw, which can be changed to a titanium model from V Seven or DSA in conjunction with a pistol grip swap.

Inline backup sight (BUS) users have many lightweight options made from both aluminum and polymer, but shooters who need 45-degree offset BUS have very few choices. While offset metal mounting rails can be used with lightweight, inline BUS set at 45 degrees, the resulting setup is unnecessarily bulky and heavy due to the extra hardware. If you can work with low-profile, fixed, offset BUS, XS Sights’ models are lighter than any others I can find. They are always ready for use and available with tritium front- and rear-aiming references.

Fans of two-point, quick-adjust slings can reduce overall rifle weight without giving up sling functionality. If your rifle has sling loops, you can eliminate separate mounting hardware altogether unless you need a quick-detach capability. Most of us need some hardware, so looking for slings that lack padding and use cable-loop attachments, such as models available from Blue Force Gear and SOB Tactical, will keep weight to a minimum.

Other relatively simple elements to the rifle diet could include changing a freefloat fore-end for a shorter version of the same make and model. In most cases, this allows use of the existing barrel nut, making the changeover easy. Replacing an existing optic just to shave a few ounces may not be cost-effective, but if you are in the market for a new one, compare weights in addition to other attributes. The same is true for scope mounts. If you are not sliding down ropes or rigging your rifle to a parachute harness as part of your night job, a lighter mount may do everything you need it to. Aero Precision’s Ultralight Scope Mount is an example that has performed well for me.

Finally, do not overlook accessories when you are reducing system weight. Smaller and lighter gun lights and/or lasers are available from companies like Inforce, SureFire and Streamlight. They may not have as many bells and whistles as bigger models, but if they perform basic illumination or aiming functions, the trade-off may be worth making.

You can see from the accompanying tables that shaving more than a pound off of a rifle does not require much effort. Even if you steer clear of the more expensive and exotic components, removing three quarters of a pound is doable using simple,  drop-in parts, but without a huge outlay
of cash

AR Component Weights


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