2015年新年伊始,西格武器公司推出了新款卡宾枪SIG MCX,为其开拓AR系步枪市场注入了新的力量。尽管该枪的外形和操作方式与AR系步枪一致,但是其内部结构却差别很大。SIG MCX卡宾枪的复进簧安装在上机匣内部,而AR系的复进簧装在枪托内,因此SIG MCX卡宾枪可以将枪托设计成折叠式,大大减小了携行时的全枪长度。该枪机匣顶部的导轨一直延伸到枪管中部导气箍上方,导轨由螺钉与护手固定,而导气箍前方的导轨则与护手是一体的。SIG MCX卡宾枪目前有2种型号,一种为采用短枪管的SBR型, At the beginning of the new year 2015, Sigurdauer introduced the new SIGMAX carbine, which has infused new forces into the AR-series rifle market. Although the gun shape and operation of the AR rifles consistent, but its internal structure is very different. The recoil spring of the SIG MCX carbine is mounted inside the upper casing while the AR recoil spring is housed in the buttstock so that the SIG MCX carbine can be designed as a folding stock and greatly reduces the overall gun length . The guide rail at the top of the gun casing extends up to the middle of the barrel of the gas tube. The guide rail is fixed by the screw and the hand guard while the guide rail at the front of the gas guide ring is integrated with the hand guard. SIG MCX carbine currently has two models, one with a short barrel SBR type,