Machine Gun: Sterling MK4 SMG

    I got a chance to work with SCH Firearms and take a look at his Sterling MK4 SMG.


    The Sterling MK4 is a personal favorite of mine. I have only owned my Wiselite Sterling a short time but was enamored by it because of Star Wars. Say what you will but George Lucas helped to make that iconic firearm recognizable by anyone who has seen the original Star Wars trilogy.

    SCH and I compared my Wiselite Sterling and the SMG off camera to see the subtle differences that make mine a closed bolt system. Wiselite modified the original bolt assembly and added a firing pin/striker.

    Below you can see the two different bolts. In 1982 the ATF ruled that open bolt designs are too easy to modify into fully automatic so all open bolts manufactured afterward are considered automatic weapons. Wiselite modified the Sterling Mk4 design to make them operate on a closed bolt. There is a length of metal that is welded inside the bolt race way. The slot in the bolt below straddles this protrusion. this helps prevent someone from merely dropping an open bolt into the Wiselite Sterling. Also the firing pin is no longer fixed but set up on a spring and hit by a hammer for the gun to fire once the bolt is closed.

    Bolt 2

    Semi Auto Bolt on the right and full auto bolt on the left. Notice the channel cut into the semi bolt

    Sterling charging handles

    Sterling MK4 charging handles.


    The longer SMG charging handle actually protrudes through the center of the bolt and into the recoil spring guide you see below.

    Sterling Springs 2

    SMG spring assembly on top. Semi auto spring assembly on bottom.

    Sterling springs

    Sterling MK4 spring assemblies


    Something else I did not mention on camera is the amount of protrusions the Sterling MK4 has. Just between my semi auto and the SMG, the SMG has an offset bayonet lug at the 7 o’clock position of the barrel shroud. It was somewhat awkward grasping the hand guard without having the bayonet lug poke my hand.

    Then there is the rest of the gun. If you recall, the Stormtroopers of the original Star Wars Trilogy all had their E-11 blasters holstered on the left. That is because if they holstered the Sterlings on the right, the mag well would poke them in the leg.


    Holstering a Sterling like a Stormtrooper is actually not really possible due to the charging handle, which was removed for the props. As you can see below, the charging handle protrudes a good inch out of the receiver.




    On the left side of the weapon you have the magazine well. Slinging this gun is not fun. There will always be some protrusion that will jab into your body. The new First Order Strormtrooper blasters, in the recent Episode 7: The Force Awakens, have been modified and the mag well is now on the right side of the receiver. Allowing for the blaster to be holstered on the right,


    However none of those issues are real deal breakers for this gun. In semi or full auto the Sterling Mk4 is a fun gun to shoot. The recoil is soft and even though the trigger is hideous looking it is not bad in terms of trigger pull. If you get a chance to play with one you will have a smile on your face. I plan to use my carbine in this season’s USPSA matches now that they have a dedicated Pistol Caliber Carbine division.

    Nicholas C

    Steadicam Gun Operator
    Night Vision & Thermal Aficionado
    Flashlight/Laser Enthusiast
    USPSA competitor

    Any questions please email him at [email protected]