Johnson Indoor Target Gun: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Johnson Indoor Target Gun
The Johnson Indoor Target Gun is a catapult BB gun that was made in the late 1940s for youth target practice.

Part 1
Part 2
Part 3
Part 4

A history of airguns

This report covers:

  • The test
  • First shot
  • Second shot
  • Adjusted down again
  • Rubber band broke
  • Now for a group
  • Proof of the pudding
  • Summary

Well, all the work we did was to get to this point. Today I shoot the Johnson Indoor Target Gun for accuracy.

The test

I shot at a target about 10 feet away. I was seated and used the UTG Monopod as a rest.

Since these BBs are only moving 126-129 f.p.s., or so, I used an aluminum foil target like the one I made for the Sharpshooter catapult gun test. We know slow-moving balls will penetrate aluminum foil readily. The target was backed by a cardboard box that stopped every BB, and then sent them back at me. More work is required on the backstop to catch the BBs successfully.

I only used a single type of BB for this test. There could be a difference in accuracy, I suppose, but it seems to me that catapults are far more forgiving of what they shoot. So, I chose Air Venturi Steel BBs.

I shot only 5 shots instead of 10. When you see the target you’ll understand why. The aim point was at 6 o’clock on the dot drawn on the foil. Let’s get started.

First shot

The first shot went high, so I took a picture of the target to show you. Fortunately the Johnson has adjustable sights.

Johnson first shot
The first shot (long arrow) hit considerably above the aim point (short arrow).

Johnson sight
The rear sight adjusts for elevation. Unscrew the knurled disk and slide it up and down. The first shot was with the sight set on the top line (blue arrow). For shot two the sight was set as seen here. Shot three was with the sight set on the red arrow line.

Second shot

Shot two was to the right and not that much lower than shot one. I could see the rear sight needed to be lowered a lot! That’s why I showed all the sight settings in the picture above.

second shot
As you can see, shot two moved to the right but not down by much.

Adjusted down again

This time I really dropped the sight. And it paid off with a shot through the dot I was aiming at! The picture is really dark, so I lightened it.

bullseye
Nailed it on shot three.

Rubber band broke

On this shot the rubber band broke, so I had to make a new one. I don’t think it affected the accuracy of the shot, however, and the shots that follow will confirm that.

Because of all the work I had done in the previous tests I knew exactly how to replace the rubber band. It only took five minutes before I had the gun back up and running.

Now for a group

Since the last shot was on target, I decided to just shoot 4 more shots without changing anything. Even though the rubber band had to be replaced, it had no affect on the sights. The gun was still sighted-in.

Four more shots went downrange. Shot 3 was a called pull to the left. When I was done I had a tight little group to show. Five shots had gone into a group measuring just 0.358-inches between centers. Sure, it was only shot at a distance of 10 feet, but that’s the nature of this gun.

group
Five BBs went into a group measuring 0.358-inches at 10 feel. Shot number three was a called pull to the left.

Proof of the pudding

Shooting this gun isn’t exactly resting. It’s a lot like shooting a flintlock. I wasn’t going to shoot another group, but I thought if I shot one more BB at a fresh target that might satisfy everyone. I figured it would sail though the bullseye. Wrong!

This time I aimed carefully and did not pull the shot, but the BB missed the bull altogether. The scale of the dime shows how close it was, so I think this shot represents the true accuracy of the gun.

last shot
The last shot missed the aim point. A fly would not have been hit. Still, I think this represents the accuracy potential of the Johnson — at least this one!

Summary

I think this Johnson is accurate enough for what it is. It’s not a 10-meter target rifle — heck, it isn’t a rifle at all! In its day it was essentially a toy.

This series has taught me a lot more about the Johnson than I ever knew. Now that I have tested it I know how to fix the rubber band so the gun performs as it should.

All the research I did on the Theraband Gold, plus watching the Slingshot Channel, plus looking at those Chinese “slingshot rifles” that are modern versions of Hodges gun, I am now interested in building a powerful catapult gun from scratch. If I do, I will take pictures and write it up for you.

46 thoughts on “Johnson Indoor Target Gun: Part 5

  1. BB,
    This has been an excellent series. I wish we had something new and quality like this these days. I got my son the SAR rifle, it is pretty good. But something simpler would also be welcome.


  2. B.B.,

    Thanks for all of your hard work and persistence to get to this point. Not bad results at all.

    Make one ehh? As I recall, your woodworking skills are akin to an angry Beaver, with a broken tooth, having a go at a downed tree limb,….. or something to that effect. 😉 I do believe that Vana2 was going to have a serious go at making one. A few others showed interest as well, as I recall. Maybe let them have a whack at it first? That is unless you have nothing else to do???? 😉

    The slingshot rifles looked quite intriguing and more simple than replicating a catapult gun like this one. All in all,… cool stuff and something more to ponder and play with.

    Good Day to one and all,…… Chris



      • B.B.,

        Metal would my choice as well, but I would do up a proto type out of wood first just to test proof of concept,… even if it was very crude. No doubt, some time spent on the net would cut the learning curve down tremendously. There is some very interesting extruded metal products out.

        The hardest part for (me) would be the trigger/release build. Much less so for you with your knowledge of historical weapons.

        Of course you know I was just having a bit of fun with you as you have self-confessed your wood working abilities. I can honestly say that my skills are not much better. Proper tools go a long ways. Give me a pile of 2×4’s, some plywood, some drywall screws (3″ and 1 5/8″) a chop saw plus a drill,.. and I can build you a super dandy work bench. That is my idea of “fine” wood working. 😉

        Chris


  3. B.B.

    As all ways, very interesting. How about using the foil in front of the putty used to catch real pellets? They might not stick, but they would not bounce back very far.
    Have a great weekend to all….

    -Y


  4. B.B.,
    With that first group, I think you would have nailed at least 3 out of 5 flies. =>
    Even for 10 feet, that’s better accuracy than I expected.
    This has been a really interesting series on catapult guns.
    Take care & God bless,
    dave
    P.S. “I am now interested in building a powerful catapult gun from scratch.
    If I do, I will take pictures and write it up for you.”
    Now THAT would be really interesting!


  5. B.B.

    I would like the see what design that you come up with for a catapult rifle!

    I plan on making a couple of them as I have a few different approaches that I want to try out. Hope that other readers will have a go at making one as well. Would be interesting to see what they come up with so we can compare notes.

    For your “trap”, try clothespining a free hanging “curtain” (a dish towel) over the open end of the box and clothespin the foil to the towel.

    Happy Friday all!!
    Hank


  6. B.B.

    Making a catapult gun… Saw an ad for crossbow-type rubber band powered “gun” that shot a bolt or 3/8″ dia steel balls. Don’t recall the velocity. Now if only I could recall the url.

    Dan


  7. B.B.,

    This has been an excellent series, quite educational and very much fun to read and reread.

    Have you given a lot of thought to just why the Johnson Indoor Target Gun is so accurate? The velocity consistency doesn’t hurt, but at such short distances, it can’t be that great of a factor. The shooter benefits from a tracer round effect, being able to see where each shot is going. But that is true of many BB guns that are inaccurate.

    It occurred to be that I can’t find an image of the “muzzle” area at the end of the gun other than one photo of the rusty specimen. Is there a short barrel, or does the BB simply fly out of the hole at the front of the carrier?

    I have heard of slingshot shooters who have incredible marksmanship Could barrels intrinsically be an impediment to accuracy, with the most accurate guns not having a barrel at all?

    Michael


    • Michael,

      There is no barrel. The shot flies out of the launcher directly.

      Rifled barrels are not an impediment to accuracy. They enhance it. But the distance to the target is a major factor. I shot at 10 feet. At 100 yards it’s doubtful this gun could hit a barn with consistency.

      B.B.


      • B.B.,

        A rifled barrel is more accurate than a smooth-bore barrel. But is a rifled barrel more accurate than no barrel at all (i.e. a barrel-less gun such as the Johnson)?

        Propellents require time and space to expand behind the projectile; therefore, a barrel is necessary. A cartridge dropped into a fire will not shoot the bullet with the force it would have in a firearm. The expanding gases need to be directed and focused.

        But what if the propelling force were something that required no expansion? What if a gun simply had a projectile “spit” out of it by an electromagnetic force or some other means that does not involve expanding gases? Might such a device demonstrate that barrels, while necessary, are themselves problematic to one degree or another when it comes to accuracy.

        Michael



          • B.B.,

            Obviously what I am suggesting is theoretical only. And besides, my only reason for thinking of it is the accuracy of the Johnson Indoor Target Gun, which has no barrel. I could be completely misguided here.

            In the real world, not a theoretical one, at least three countries (easy to guess which three) have worked to develop electromagnetic guns (I believe artillery) with some success.

            Michael


            • Very good points Michael. A rifled barrel stabilizes a projectile so that aerodynamic forces don’t make it tumble, but I am not sure if it is inherently more accurate than a smooth barrel, or as you suggest, no barrel at all.

              Current tank artillery uses smooth barrels and sabot cased projectiles that – like a good pellet or an ancient arrow – are stabilized by shape, and the drag it produces.

              As a reference, search in Wikipedia for “Rheinmetall_Rh-120”

              Henry



  8. Michael,

    Barrels come rifled (by various styles/designs and methods of fabrication) they can be bamboo, iron, carbon steel, brass, bronze, copper, aluminum, SS and many other materials.

    Unless one subscribs to the strict definition of barrel as an item that contains another thing; say, liquid or dry goods.Doesn’t an electromagnetic barrel (IF NOT an actual metal barrel as used in many of the current examples) in a rail gun actually contain the round until it goes ballistic.

    The catapult gun seems to me to be a progression from the throwing arm/hand of a human?

    Most weapons trace back to a human skill magnified through the weapons Maker’s art.

    Just my musings…

    shootski


    • Shootski,

      You and Henry_TX above both point out that as long as the projectile is rotating (arrow, smoothbore slug with a particular shape), it has a better chance of being consistent in its flight.

      A quarterback throws a football in a manner which makes it spin. No barrel, but the faster the ball rotates, it seems, the more stability (perhaps through a gyroscopic factor?) it has in flight.

      Michael


      • Michael,

        From what I have seen of the BIG rail guns,… the projectile is fired from a square/rectangle shaped barrel, enclosed in a break away case, and the tail fins induce a stabilizing spiral to the projectile. We already have pellets in plastic shells. Why not a magnetic friendly projectile (steel) in plastic shell, instead of lead?

        Chris


        • Chris (and others who have chimed in),

          To me the future of projectile-weapons is not air or combustion-generated expanding gases. Of course there is more progress in those to be made. But it seems to me that electromagnetic and sonic, perhaps, microwaveable, and laser, weapons are the future of applied destruction. The increased velocity that friction-less space provides, as opposed to atmospheric travel, also makes such weapons seem practically limitless in their capability of destruction.

          A hydrogen bomb is incredibly difficult for just anybody to produce, and also difficult to deliver to a target thousands of miles away. As an American, my reaction to all of that is, “GOOD!” Humanity does not need a half-dozen or dozen nations throwing those things around.

          But a small, rail-mobile weapon with 23 million foot-pounds of destructive energy? I am not anti-gun in the least, but I wouldn’t want the world to go there, period.

          Recently we commemorated the 100th anniversary of the Armistice that ended The Great War. I had nine great uncles who were combat veterans in that conflict, and each experienced the horror of chemical warfare first-hand. War is hell enough. We do not need to make it even more so.

          O.K., I am off of my soap box.

          Michael


          • Michael,

            That is certainly the “big picture” of things. I am of complete agreement. I was thinking more along the lines of hobbyist use.

            Unfortunately, governments will always be racing to the latest, greatest and most destructive things. If “they” have it, then are we not better off to be one-up on that,.. ehh? Thank heavens for high quality surveillance and intelligence,… which in itself is a race.

            I agree that this is a great place to discuss ideas,.. student to student. Someone is always thinking outside the box and we have people here with such varied backgrounds to offer their own pin-point perspective,.. often from first hand experience.

            Good luck making a catapult gun. The sling shot rifles have my interest more. I figure them to be easier to use and to make. If someone can shoot a slingshot or wrist rocket with good accuracy, then a slingshot rifle ought to be the ultimate in ease of use and perhaps accuracy too. Draw length could be greatly increased as well and in doing so, increase power.

            Chris


  9. B.B. and readership,

    December 7th 1941, a day that will live on in infamy!

    Please remember the sacrifices of the sailors, soldiers, airmen and civilians at Pearl Harbor this day!

    Hand Salute!

    shootski


  10. The old TV’s projected electrons in a vacuume using magnetic fields. They are accurate and can achieve high velocities. So a magnetic rail gun with a self stabilizing projectile should work fairly well in an atmosphere. The U.S. and China navies are building them now.

    Shooting bbs with a magnetic rail gun on a small scale should be a simple device using a micro computer to time the electro magnets and rheostats for sighting in. Power could be the problem. It might need a car battery, but the new lihium ion bateries should do it. A short nonmagnetic breach could hold the bbs in place until shot. A repeater wold be easy.

    I know there is enough expertise on this blog to design one and build it. Would it be a airgun?

    Don


    • Benji-Don,

      Capacitor(s) is the answer for something that shoots one round at a time. As long as the capacitor has enough time to recharge it can be VERY powerful from a relatively low power and/or slow source.

      shootski


      • Shootski,

        After some pondering,…. why not? Figure in the cost of a compressor and tank and a nice PCP and you have a pretty good $ start on something TOTALLY different. Yes,… with a capacitor bank and battery affixed,.. it would pretty much be a bench set up,… but hey? The Red Wolf does cock the hammer in a similar manner,… but does not supply the power to actually move the projectile. The 3,500 psi air does that.

        As you said,… “Just my musings”,….. Chris 😉


    • Don,

      It would be very cool, but it would not be an air gun. Expanding air without combustion = air gun.

      A Daisy 179 is not an airgun. It is essentially a catapult enclosed in a Colt Peacemaker-like enclosure.

      Michael


      • Michael,

        I don’t think rail guns of any power will be classified as an airgun, but i believe it will be based on the potiental to exceed the energy of powder burners.

        Don


        • Don,

          Your description a few posts above is far beyond my scientific education (or lack thereof), but every single thing you wrote makes sense to me with my limited understanding. The ever-increasing ability to create portable, regenerating power is impressive. It makes me believe that what you describe is entirely within out grasp.

          One thing you mention I do have quite a bit of experience with is the electrolytic capacitor. It is, in my opinion, still a marvel. As a hobbyist in the field of vintage vacuum tube amplifiers, I am well acquainted with and respectful of them. Everyone should know the one-hand-in-pocket rule and a couple reliable methods of discharging them.

          Michael


  11. BB
    Looks like the sights work nice.

    I’m guessing the rear sight is a peep sight. What does the front sight look like also when looking through the sights?

    And you know me. I would like to know the limit of the guns distance it can still shoot accurately at. What about maybe a test where you back up about 2 feet at a time and do some 5 shot groups to see. And of course I don’t only mean fly size targets. What about styrofoam cups at say 15 feet. Can we see if it’s still accurate at that distance for the cup?



      • BB
        Ok I checked out the sights. Forgot you showed them.

        And cool I’ll be waiting for the styrofoam cups test. I’m going to make a prediction. I think the gun will be able to hit the cup at a pretty reasonable distance without even having to put alot of holdover in the sights.

        If the gun shoots like I think it will. It will be a nice basement or bedroom plinker.



  12. B.B.,

    You are a natural educator. Yet again you have started discussions about related subjects with questions, possible answers, and more, the very definition of the discourse of learning, student-to-student discussion. I wish I could do that consistently in my classrooms.

    I thought aloud above about my Daisy 179. As I can watch the BB in flight, I am able to adjust my aim accordingly. There really is not much of a barrel with a 179, is there? It is basically a pitcher that tosses a ball, no?

    My 179 is absolutely consistent, however. It pitches that BB at the same speed (probably) in the same precise direction (definitely) again and again. With three or so practice shots, I can then hit the same quarter-sized knot on the top rail of the fence on the side of my yard from 10-12 feet.

    By the way, I have now reread this series five or six times. I think I, too, must construct a catapult gun a la the Hodges. Given my lack of any sort of woodworking and metalworking skills, it will probably look like a Frankenstein’s bicycle or something, but I have to do it.

    See the influence you have on some of us? Man alive.

    Michael


  13. Well, here I sit. It is almost 4:30 PM and there is almost a foot of snow outside and it is still coming down. There is a pot of beef vegetable soup starting to cook on the stove and a chocolate cake waiting for dessert, well most of one anyway. I guess I should have been shooting some, but just sitting around with Kathy and watching it snow was too relaxing. Oh well, maybe tomorrow.


    • RR,

      Better you than me (snow), with work early Mon.. Sounds nice (and relaxing) and the dinner and desert sound yummy,….. then again,…. my mid section is telling me,….. ? 😉

      Chris


      • Chris,

        I will not be going anywhere tomorrow. Only a fool would be out in this mess. They do not pay me enough for that.

        I have my laptop with me and if I can connect, I will work from home. If not, I guess I will just have to go out and play in the snow with the dog. Either way will be just fine with me. Maybe a combination of both.


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