A SIG MCX-SPEAR LT bolt and recoil spring assembly ... Unlike AR-15 designs, which require a fixed receiver extension to house the buffer and recoil spring, a design like the MCX that follows ...

the MCX VIRTUS utilizes the proven SIG Sauer short-stroke piston system and unique internal recoil system that eliminates the M4-style buffer tube. The result is a compact, light-recoiling ...

This is Sig Sauer's answer to the Army requirement for a Next Generation Squad Weapon Rifle. The MCX Spear is a contender to replace the M4. Military Times © 2025 ...

Hot off its new contract with the U.S. Army, Sig Sauer has ... s popular line of MCX gas-operated piston AR-15-style rifles. But MCX has the benefit of not needing a buffer tube in the stock ...