Analysis of information sources in references of the Wikipedia article "SIG MCX突擊步槍" in Chinese language version.
The MCX has the familiar AR upper and lower receiver layout that we know, but some caveats have been added here. The upper receiver is hardened in select areas, and Sig has developed replaceable parts for those areas that wear the most. One such part is the metal cam-path insert on the side of the upper receiver. Other replaceable parts include a feed ramp insert and the ambidextrous charging handle latch. These items are all steel inserts or pins. The forward assist has an aluminum housing that can be replaced if it wears out. These features reveal that the MCX was meant for long-term use in harsh conditions. In essence, you won’t have to scrap the upper receiver after hard use, only replace some parts. The lower receiver’s controls require no retraining, as they are the same as an AR’s, while the magazine release, bolt release and safety selector are all ambidextrous. Aftermarket drop-in triggers will be right at home, too.
The MCX has the familiar AR upper and lower receiver layout that we know, but some caveats have been added here. The upper receiver is hardened in select areas, and Sig has developed replaceable parts for those areas that wear the most. One such part is the metal cam-path insert on the side of the upper receiver. Other replaceable parts include a feed ramp insert and the ambidextrous charging handle latch. These items are all steel inserts or pins. The forward assist has an aluminum housing that can be replaced if it wears out. These features reveal that the MCX was meant for long-term use in harsh conditions. In essence, you won’t have to scrap the upper receiver after hard use, only replace some parts. The lower receiver’s controls require no retraining, as they are the same as an AR’s, while the magazine release, bolt release and safety selector are all ambidextrous. Aftermarket drop-in triggers will be right at home, too.
