Shooting the Sjogren Inertial Shotgun

When I filmed this, I had limited time and figured I would do the shooting first and then film the history and disassembly of the gun afterwards. Alas, I ran out of time and never did get that part completed. I will follow up with a video on the history of the Sjogren the next time I have access to one, but I think the shooting footage worth posting by itself. Also, please note that I did not have my proper high speed camera on this trip (I had not anticipated being able to shoot anything!) and so we used an iPhone slow motion function instead. Happily, the Sjogren operates slowly enough for that substitution to still work decently.

Anyway, the Sjogren is a very unusual system, an internally-locked semiauto shotgun developed by a Swedish inventor and produced in Copenhagen. A rifle variation of the system was tested by a few militaries but never put into production. A few thousand of the shotguns were made and sold commercially prior to World War One. You can find more information on them in my full article.

As I say in the video, I found the Sjogren to be a quite pleasant shotgun to shoot, especially for being chambered for 12ga shells. I had a Walther toggle-locked shotgun out at the range the same day, and the contrast between the two was quite significant!

17 Comments

  1. Thanks for bringing us another unusual/rare firearm and taking the time to test fire it, which makes it all the more informative. My patreon dollars are always well spent with you. Also thanks for including the U.S. patent.
    Jim

    • The bolt holding back on each round is fairly common on semi-automatic tube fed shotguns. Mr. Browning built that into his Auto-5. The reason is that shot shells, with their heavy lead charges don’t want to move very fast out of the magazine tube, and the magazine tube spring can only be so strong or you couldn’t load it, so the chances of the shell not getting in place to be fed is great. What happens is a mechanism holds the bolt open each time it goes back, so it waits there for the shell to come back into position, at which time the base of the cartridge releases the bolt to go forward.
      Jim

  2. “(…)Sjogren operates slowly(…)”
    I want to point one matter not mentioned – most of 1890s shotshells have paper bodies, unlike modern polymer ones. This mean that in dawn of 20th century self-loading shotgun designer need to make them to cycle in more delicate/smooth manner that modern self-loading shotguns are supposed to (c.f. Browning Auto-5 of similar era).

    • Design for what you have ON HAND, not what you WISH to have. Unless you’re looking to reinvent the entire shotgun shell’s construction (assuming early 20th century person), don’t design the gun for harsh extraction.

  3. Owning one Sjögren shotgun (and having fired it), I am eagerly waiting for your disassembly video, Ian.

    Greetings from France. 😉

  4. Most semi-automatic firearms have a recoil impulse when the recoiling parts strike the rear of their limit of travel. They also get a second recoil impulse when the recoiling pieces move back into battery. Spreading them out over time makes it seem like two 1X recoil impulses, instead of one 2X recoil impulse. Of course constant recoil guns where the bolt velocity drops to zero at the rearmost of its travel have 1X = 2X = 0 recoil impulse. For those more interested use your favorite search engine to look for elastic vs. inelastic collisions. Or look at Ian’s video on the Lahti anti material rifle for another example of what I’m talking about.

  5. Max Popenker opines that the inertial bolt system doesn’t work for a high pressure cartridge like found in rifles. Do you know if the test and evaluation report for the Sjogren rifle in the Pattern Room still exists? It does seem like an incredibly elegant system for a self-loader.

    • Excepting long recoil, the task of cocking the action and ejecting the empty case are all done through simple blowback elements that is gained momentum and residual gas which remaining short in inertial system by cause of its; Double step first collecting and then discharging with wastes momentum and small amount of residual gas through the fact of leaving projectile in this rather long responcing time. Therefore if ; The bolt carrier not being of biggest mass possible, the other parts of gun being not of smallest mass possible, the case being of overbottlenecked, mass of projectile rather big and the elasticity of energy collecting unit over standart… The possibility of inertial system in rifles seems impossible.

        • We all know Sjogren first tried its working system in rifles which the features of its cartridge was unknown and later applied it to shotguns which should be lower muzzle velocity. A service rifle working sometimes should not be interesting for purchasers. It should work in all times. Its initial round might be black powdered or another kind of propeller and projectile might be overweighted which all delivering slow muzzle velocity which unacceptable in todays standarts. We also should remember that, Mauser whose experimental inertial rifles worked in single step working sequence rather than Sjogren’s two step and giving more shorter responce time, found unsatisfactory.

  6. 50 Years ago I saw the first Sjögren shotgun described in a book and I never lost interest in this weapon. Six years ago I could buy one and tried to hunt ducks with it. That failed, because the gun shoots a little bit too low and right. But I like it very much. Benelli took the technique of the Sjögren, built it into a modern selfloading shotgun frame and sells it under the name Vinci. Its just the same function principle in a modern shotgun.

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