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

Co-Founder of KRISSTALK forums, an owner’s support group and all things KRISS Vector related. Nick found his passion through competitive shooting while living in NY. He participates in USPSA and 3Gun. He loves all things that shoots and flashlights. Really really bright flashlights.

Any questions please email him at


  • datimes

    Damn you TFB. It’s all your fault I had to go out a buy a nice MP 40 last week.

  • Stephen Beat

    Like a lot of guys who served in the British Army in the 60s and 70s, I loved the Sterling when I did my army orientation. Obviously, vehicle crews like it, and it was popular in Northern Ireland (where the L1A1 was too unwieldily for house to house). I believe some saw service as late as the First Gulf War. I guess it’s a bit of a ‘Brit thing’, as it’s iconic format is so reminiscent of the STEN. The info about the Lanchester mag was new to me, that was very interesting!

    • Yep. I think some places in India are still using the Sterling.

    • FWIW: Sterling was also the prime manufacturer of the Lanchester SMG. George Lanchester was rather put out when the company transitioned to George Patchett’s design.

      • Stephen Beat

        Really? That’s very interesting. Thank you. I don’t know much about the Lanchester – other than it was a heavy design and was mainly used by the Royal Navy. Will have to look a bit more into this!

        • Jonathan Ferguson

          The lineage is apparent when you look at the prototype Patchetts.

  • BattleshipGrey

    I was pretty tempted to buy one of the Wiselites when they came out, but as usual my wants and funds were not in line. Maybe some day.

    While visiting the state firearm crime lab, I got to fondle a Lanchester after I asked the director what his favorite gun in the whole inventory was. It was definitely heavier with the wood stock, but it felt great.

    • I missed out on the Wiselites. I had only started getting into guns in 2012. Fast forward to last January. I built a 9mm AR carbine to trade for the Wiselite. I am glad I did. It is such a fun gun to shoot.

    • The bronze magazine well on the Lanchester doesn’t help either.

  • Major Tom

    Now for the ultimate question: Are you a better marksman than a Stormtrooper?

    • LOL Easily. You can’t see it in the Stormtrooper mag dump but when I hip fired the Sterling, I missed the steel. So I was able to walk to rounds on target and hit it.

    • Nicholas C

      Considering I was able to walk my shots onto the target, yes.

    • M.Mitchell Marmel

      ‘Nuff said. 😀

  • David

    SBR the Wiselite, its worth it. Just got my forms back and cut down the factory barrel a few weeks ago.

    • Yeah I would do it just so I can thread the barrel and put a suppressor on it.

    • Nicholas C

      What is on the end of your Wiselite? Doesn’t look like the wiselite barrel nut.

      I would cause I want to suppress it.

      • David

        It’s a cap a member machined on the Uzi Talk forum. Shorter than the original barrel nut and looks a little better IMO. I thought about suppressing it but decided not to. I think most fellas cut/thread it just beyond the original barrel nut to suppress.

  • TheNotoriousIUD

    Id rather carry one of these so I could actually hit something.

  • claymore

    I still have one and it has been a registered SBR since 1985. The only problem is if you are left handed the mag sticks far out from your body during normal carry. One most remember and allow for cleareance so not to bang into things or get hungup in the bush.

    • Yeah that is a consideration. Do you have issues with brass across the face?

    • I distinctly remember seeing photos of British troops carrying Sterlings vertically on their right hip at mid-belt level. Alas, I don’t know how they managed it. Did their web gear clip into or onto the magazine well? Presumably you could only have a short magazine or no magazine inserted at the time.

      • claymore

        They do come with a short mag 10 Rds I believe.

        • I haven’t seen a 10 rd mag. Other than custom made ones from original 34 rd mags.

        • Jonathan Ferguson

          There was never a short mag issued, only available commercially from Sterling. Not sure where Daniel has seen this holstering/slinging arrangement, but it would have been for carriage only, most likely by Paras.

          • Collector Grade Publications’ title “The Guns of Dagenham” shows that such a carriage device was displayed in the earliest Patchett Machine Carbine manual from 1943. However, the text indicatives that the device was never adopted. I could have sworn that I’ve seen photos of troops carrying the Sterlings in a similar fashion, but that would have been ~40 years ago.

          • Jonathan Ferguson

            Ah, OK. You may have done, perhaps a trial?

          • I may have just seen reprints of the manual’s photos. However, I want to say the troops were wearing DPM, which would rule out the Patchett manuals. Perhaps it was in sales photos from Sterling?

            I just remember thinking that it was a clever and compact carriage system, yet I was puzzled how they were not getting jabbed by the magazine or magazine well.

          • claymore

            Well I guess mine just jumped all by itself in this ones box and the genuine L-34-A-1 that I have too they both came with one.

          • Cymond

            Was your Sterling issued to you, or did you buy your Sterling?

            Because if you bought it, that could explain why it came with a commercial 10 round magazine.

          • claymore

            Bought them both, but the L-34-A-1 was a genuine military issue.

          • Nicholas C

            Got pics of the 10 rd mag?

          • claymore

            No not here.

    • Bill

      I hate getting hung up in the bush.

  • Pete Sheppard

    Nice video. It seemed extremely controllable. Was that the gun or shooter? The mention of how the off-set cartridge (NOT ‘bullet’! :p) would help prevent out-of-battery firing. Also, how hot does that barrel shroud get?

    • It is the gun. The recoil is a very pleasant experience. Even in semi auto especially compared to my CZ Scorpion.

    • It is very controllable—–

    • Nicholas C

      Not hot at all. But I only did a 50rd mag dump and as you saw it did not feed all of the rounds.

  • Bub

    I got to shoot a suppressed model at an event once and these things rock. Shooting one at the new USPSA PCC matches would be a hoot. I had hoped to use a M1 carbine, but when the rules came out they don’t qualify for those matches. Maybe a new PCC will have to go on my shopping list.

  • Leftie

    The Sterling’s magazine well on the left has some advantages firing from a vehicle’s ports or when lying down on the ground.

  • Evil_Bonsai

    Now if only someone would make, ala the new StGs, a newly made Sterling…

    • Wetcoaster

      Actually, a 16 inch barrel would be about the right length if you change the handguard to something like the suppressor body of the integrally suppressed Sterling

  • Devil_Doc

    1) What magazine is that? 2) Will SCH build a semi auto from a kit? Does anyone know of a gunsmith that will build a Sterling from a parts kit? 3) I’m not sure if WiseLite welded material to the bolt. Usually, builders will just cut a channel down the bolt to allow the striker to reach the firing pin.

    • 1) Which magazine are you referring to? 2)No SCH does not make anything. Proto-Ordnance might be able to make one for you. 3) They did not weld anything to the bolt. It was machined.

    • Nicholas C

      Which magazine are you referring to?
      SCH does not make firearms.
      Check out Proto Ordnance.
      Wiselite did not weld material for the bolt. They removed material.

      • Devil_Doc

        1) There is a picture of 2 springs, the end cap, and the firing pin. It looks like there is a magazine in the pic, that’s the one I was asking about. 2) Thanks for the info, i’ll check it out. 3) The original article said “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.” Is this saying the bolt is modified by welding the bolt, or the FA feature is limited by welding somehow? Usually, a pin is welded through the grip/selector to prevent the selector from reaching the FA setting, and the bolt is modified to operate from the closed position with a striker added.

        • Nicholas C

          The magazine is the Tapco polymer Sten Mag.

          The welding is in the bolt raceway. I.E. Inside the receiver. Not the bolt.

          • Devil_Doc

            Ah, thanks for clarifying. Also, thanks for telling me about Tapco Sten mags.

  • gunsandrockets


    Next I want to see extensive reviews and videos of firing the Australian Owen and F1 SMGs.

    • Unfortunately I do not think SCH Firearms has them. Next I plan to shoot their STENs.

    • Nicholas C

      Sadly he does not have those. I am thinking of doing a similar article on his STEN guns.

  • Give me all of your hate. It looks like an improvised gun, like the sten, or those blowback open bolt guns you can make from a banana, 1/16th drill bit, and some parts from Home Depot.

  • Blake

    “Hokey religions and ancient weapons are no match for a good blaster at your side, kid.”

    Cool article, thanks.

  • nick

    Extra cool factor, we had these mounted on our Canadian dispatch riders bikes (MT-500’s) note the mount just aft the seat on the right. Most of us slung them, as they had a habit of not being there after a bit of “Enduro-ing” !!

    (bonus points for identifying the AFV in the background 🙂

  • John McPherson

    I do wish you had discussed the Sterling magazines, as they are by my judgment the best hi-cap 9mm mags ever made. You can load them fully with only fingers and no blood shedding at all.

  • John McPherson

    I see also there is discussion here about the Lanchester which was a direct copy of the WWI German sub gun designed by Schmeiser (not the M38/40 of which the mag was his contribution).

  • George Parker

    This was my personal weapon while serving for more than a decade before switching to the first batch of SA80. Grrrrr.
    SMG= excellent for CQB and trench clearing but not much else. Reliable, easy to store in a vehicle too. Always thought a forward folding magazine housing would have made it easy to conceal.
    The silenced version was something else, whisper quiet and deadly. This makes me feel nostalgic, sniff sniff. Violins please.

    • Gunner4guy

      Agree re the Mk5. Friend has one that I get to shoot from time to time(also a PPsh 43 and other ‘toys’…..) I like the balance much better than the MP5SD’s we had in our agency’s SRT. Rate of fire is better as well especially using subsonic ammo.

      • George Parker

        The Mk5 hush puppy is still used today.

        • Gunner4guy

          Why am I not too surprised…LOL! Willing to bet not only in Her Majesty’s Armed Forces either. Haven’t checked prices lately but my neighbor offered to sell it to me for $17,5K a couple of years ago…sigh, had just bought another ‘toy’ a week prior & had to justify IT to the wife… A 2nd one right away and….. another sigh.

          • George Parker

            It is one weapon I can see being seriously restricted. Probably for good reasons but lets not go there.

          • Gunner4guy


  • William Elliott

    note: I think you got your description backwards on the bolts as the one on the right has no channel and an obvious fixed firing pin. SMG on the right, Semi-auto on the left.

  • Mikial

    When I started doing private security work in Iraq in 2004, we ran across all sorts of old and exotic weapons. One of the guys on my team had acquired a Sterling somewhere and actually used to bring it with him on the road missions. The rest of us had AKs. I was well aware of the open bolt design, and wasn’t especially comfortable with him having it locked and loaded in the same vehicle with me, but he was careful with it.

    One day as we were heading north on Route 1 between Samarra and Tikrit he and I were in the second seat, and we got into a traffic accident with an Iraqi in a pretty big truck that crossed into our lane. We weren’t wearing seat belts (because of how we had to sit in order to provide security out the sides and back) and we had several of those black footlockers they sold in the PX full of gear in the very back of the vehicle. During the accident, all those footlockers came crashing forward and as our Suburban was bouncing off the truck and sliding across the lanes before crashing into the guardrails, I remember that one of the thoughts in my mind was wondering where that bloody Sterling was pointed as he got hit full in the face by a footlocker full of gear. I didn’t want to survive the crash just to get shot by one of my own team member’s weapons.

    It ended up okay. I didn’t get shot, we cross-loaded into another vehicle and went to the nearest FOB. He was the only one hurt (concussion) and the rest of us headed on to our destination. Cool gun, but not especially practical for vehicle security work.