SIG just announced a new and unexpected version of the MCX. The MCX-R Regulator appears to use an upper receiver based on the MCX Spear-LT with a traditional style lower receiver without the option of a pistol grip and a Magpul stock. You can use any Mossberg 500/590/590A1 style stock, but I think most people will leave that part as-is. The lower receiver has an integrated ARCA between the magazine and the trigger guard as well as a fully ambidextrous 30 degree safety paddle, bolt catch/release, and magazine release. The trigger is a proprietary SIG 2-Stage match trigger so out of the box you won't have any options, but you can expect Geissele and others to start making their own trigger in the future.
Two calibers will be offered at launch: 5.56mm and 7.62x39mm. Here's a run down of the different models:
SKU: RMCXR-556N-16B
Caliber: 5.56mm NATO
Barrel: 16"
Barrel Material: Cold Hammer Forged Carbon Steel, FNC Finish
Twist Rate: 1:7"
Trigger: 2-Stage Match
Capacity: 10 Rounds
Stock: Magpuls SGA Stock - Mossberg 500/590/590A1
Finish: Reduced Weapons Visual-IR Signature Gen II NiR FDE Cerakote
Weight w/ Magazine: 7.9 lbs
Length: 39.1"
Height: 5"
Width: 2.4"
SKU: RMCXR-556N-16B-RX2
Caliber: 5.56mm NATO
Optic: Romeo2 3 MOA Red Dot Pre-Installed
Barrel: 16"
Barrel Material: Cold Hammer Forged Carbon Steel, FNC Finish
Twist Rate: 1:7"
Trigger: 2-Stage Match
Capacity: 10 Rounds
Stock: Magpuls SGA Stock - Mossberg 500/590/590A1
Finish: Reduced Weapons Visual-IR Signature Gen II NiR FDE Cerakote
Weight w/ Magazine: 8 lbs
Length: 39.1"
Height: 5.5"
Width: 2.4"
SKU: RMCXR-556N-762R-16B
Caliber: 7.62x39mm
Barrel: 16"
Barrel Material: Cold Hammer Forged Carbon Steel, FNC Finish
Twist Rate: 1:9.5"
Trigger: 2-Stage Match
Capacity: 10 Rounds
Stock: Magpuls SGA Stock - Mossberg 500/590/590A1
Finish: Reduced Weapons Visual-IR Signature Gen II NiR FDE Cerakote
Weight w/ Magazine: 7.9 lbs
Length: 39.1"
Height: 5"
Width: 2.4"
FAQ's
Is it compatible with AR triggers?
• No – it is a proprietary 2-stage match trigger with a 4.5-5.5lb pull.
Is it compatible with other MCX upper receivers?
• Yes – the REGULATOR is compatible with all MCX upper receivers and swappable at the user-level.
What is the muzzle thread?
• 1/2x28 (5.56); 5/8x24 (7.62)
Will it work with standard AR magazines?
• Yes – the lower receiver is fully compatible with all STANAG pattern magazines.
Is the Magpul SGA590 stock adjustable?
• Yes – the stock comes with a total of (4) spacers and (2) cheek risers to allow for user adjustability.
Is the rifle compatible with other stocks?
• Yes – the stock interface should accommodate most 500/590 style stocks that do not have a pistol grip.
Why is the ARCA Rail integrated on the lower receiver?
• The integrated ARCA Rail lower receiver allows for better balance when the rifle is mounted to ARCA compatible tripods without interfering with magazine removal/insertion or the rifle controls.
What is the recommended optics mounting height?
• The lowest possible mounting solutions are most ideal for the MCX-R (i.e. absolute or lower).
