The SIG Sauer MCX is shipping in the US in the next week. I got the chance to fire the 300 Black out version and had the chance to take a closer look at the system. The basic models will be the 9” pistol and the 16” rifle. The 5.56 and the 300 Blk versions will be the first out of the gate.
The MCX lower is a proprietary lower receiver that cannot be used with a regular AR15 upper, as there is no way to attach a buffer tube assemble. Instead, the receiver end is a solid piece with grooves on both sides to allow users to attach stocks of their choices. This is possible because the MCX operating system has the returning spring captive within the charging handle inside the upper receiver.
The gas regulator of the MCX upper can be accessed by removing the handguard. The handguard is fastened by the front pivot pin. Once the front pivot is pushed out, the handguard can be slided out. The barrel can also be swapped out by loosening up the 2 screws that hold the barrel assembly to the receiver.
The MCX in 300 Blk has a recoil spike similar to a DI gun. Normally, push rode driven systems using the buffer assembly of a regular DI AR tend to have sharper recoil. The MCX in 300 Blk shoots even smoother than a SIG 516 in 5.56. The left side folding stock is a bit different from the traditional European right side folding stock. Instead of giving the stock a "strike" to crack it open like one can do with a Swiss Arms, the user has to grab the stock and pull it. The positive thing with the left side folding is that it won't interfere with ejection and allow any stock design.
The MCX lower is a proprietary lower receiver that cannot be used with a regular AR15 upper, as there is no way to attach a buffer tube assemble. Instead, the receiver end is a solid piece with grooves on both sides to allow users to attach stocks of their choices. This is possible because the MCX operating system has the returning spring captive within the charging handle inside the upper receiver.
The gas regulator of the MCX upper can be accessed by removing the handguard. The handguard is fastened by the front pivot pin. Once the front pivot is pushed out, the handguard can be slided out. The barrel can also be swapped out by loosening up the 2 screws that hold the barrel assembly to the receiver.
The MCX in 300 Blk has a recoil spike similar to a DI gun. Normally, push rode driven systems using the buffer assembly of a regular DI AR tend to have sharper recoil. The MCX in 300 Blk shoots even smoother than a SIG 516 in 5.56. The left side folding stock is a bit different from the traditional European right side folding stock. Instead of giving the stock a "strike" to crack it open like one can do with a Swiss Arms, the user has to grab the stock and pull it. The positive thing with the left side folding is that it won't interfere with ejection and allow any stock design.
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