When I started putting together my first AR-15, my goal was to keep it fairly light weight so that it would be easily maneuverable for me (despite not being blessed with an abundance of upper body strength). In my research, I found several different approaches to custom rifle builds in the interest of weight saving. Most “lightweight AR-15 builds” included shorter and thinner barrels (for example, 14.5″ pencil profile barres with 1.5″ compensators/flash hiders welded to the end), and minimal accessories. Beyond these common weight saving measures, there are other additional approaches to minimizing overall rifle weight: choosing a lightweight AR-15 lower. Here are three examples of lightweight builds with different types of lowers, and the resulting overall rifle weight.
Using Polymer AR-15 Lowers
Jon from the YouTube channel chaos311clarity has a lightweight AR-15 build he calls his “Chaos Carbine,” that measures in at 6.2lbs (unloaded), and one of the chief components of this light AR is his Plum Crazy polymer lower. It also features a DPMS upper (sans brass deflector and forward assist, in the interest of saving weight), a Daniel Defense pencil profile barrel (with Ares Armor Effin-A compensator), and a Giessele Super Dynamic 3 gun trigger.
Using Carbon Fiber AR-15 Lowers
Recently, I received a rifle from Windham Weaponry for test and eval (T&E) that features upper and lower receivers of a molded fiber composite (that includes 40% carbon fiber).To see my first impressions of it, check out the embedded video above. Unloaded, this flattop rifle weighs only 6.0lbs (including sights). Because this is a T&E gun, all the parts on it are stock, with the exception of the Troy fixed Tritium iron sights (borrowed from my AR build detailed below). The stock rifle comes with a polymer double heat shield handguard, a 16″ M4 profile barrel tipped with a standard A2 flash suppressor, a stock single stage trigger, an A2 style polymer grip, and polymer six position telescoping buttstock.
Using Aluminum AR-15 Lowers
When I started putting together my custom AR-15, “Bruce,” I was also interested in weight saving, but preferred an aluminum lower. My lightweight AR-15 rifle features an aluminum billet LMT Defender 2000 lower, and weighs in at a somewhat heftier 6.6lbs (unloaded). In the linked video, my rifle features a Daniel Defense DDM4V7 upper with 16″ pencil profile barrel (with a 1.9″ Daniel Defense flash suppressor) a Magpul ACS-L buttstock, Troy Tritium round aperture fixed iron sights, a V-Tac Upgraded Wide Padded Sling, and the stock LMT Defender ergo grip and stock 2 stage trigger.
What parts would you like for your lightweight AR-15 builds?