Difficult to mount rails to, relatively brittle, and prohibitively expensive, the material can be a tough sell. However, it’s also astoundingly lightweight, conducts little heat and when it does, maintains its shape better than steel. AR-15 rifles were some of the first firearms to feature carbon fiber, but in their original form, were a poor host. Original Colt M16A1-based rifles are well-balanced due to their government-profile, pencil barrel. This makes the weight savings afforded by carbon fiber superfluous.
Today, however, many modern AR-15 rifles feature-heavy bull barrels or piston-driven bolts; both greatly shift the weight of a carbine towards the muzzle, especially when paired with an aluminum rail. This setup uses a mechanical advantage to feel heavier to the shooter, much like holding a weight on the end of a long stick. Here, is where featherweight composite furniture really comes into its element. SIG Sauer thought so as well, which was the impetus behind their new SIG 516 Carbon TS carbine.
The SIG 516 Carbon TS is a short-stroke, piston-driven rotating bolt AR-15-style semiautomatic carbine chambered in 5.56x45mm and .223 respectively. Feeding on standard AR15/M16 STANAG magazines, the Carbon TS appears mundane on paper; simply a piston carbine with pricey furniture. That is until shooters take a closer look and what’s under the hood.