SKBR Sonic Broom's Knex Rifle




Introduction: SKBR Sonic Broom's Knex Rifle

About: I like to make things and invent new products. i also like to cook read books and play with KNEX LEGO and other things. My other main interest is companies i like to read about them learn about them and keep...

SKBR Sonic broom's Knex rifle please vote for me in the rubber band contest! and subscribe.

I wanted to try and make a Knex rifle since all my guns so far have been pistols and little compact guns; so here is my first Knex rifle. It shoots yellow rods, and has an internal mag pusher.

Just so you know this is my first large gun so it may not be up to today's standards but I think it came out pretty good for my first try at this. I had to mod and change a lot on this gun but after some testing and work here is my new gun - SKR Sonic broom's Knex rifle!


Very comfortable handle

Pin guide

pretty strong

trigger can hold lots of bands and is Very comfortable

stock holds extra ammo

looks cool IMO

strong stock

rail on top to attach attachments

Very easy to mod and change around


Not that good of range - about 20 feet. What do you think I could do to improve the range? Please post your ideas in the comments.

non removable mag

Jams sometimes

Please give me your feedback and ideas on how to improve my future projects and posts.

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    23 Discussions

    is it possible for you to make instructions for it, because i really like it and would absolutely love to build it

    Thanks if you liked this you might like some of my other instructables so please go check them out and tell me what you think!

    This looks pretty sweet man! As far as improving range I would make the magazine further from the ramrod, so it barely contacts the ammo. This will increase the amount of energy transferred to the ammo. Also make the length of barrel after the magazine minimal to reduce friction. I am aware the barrel does add to appearance.

    Otherwise, good job! I may use that stock ammo holder in a future build.

    3 replies

    I added the barrel to stop the ammo from spinning out of the gun. also could i just put some more spacers on the ram rod to stop it from going in so far? thanks for your ideas and feedback!

    Adding spacers to the pin will probably not help power because you are losing pin draw distance. A quick summary of this concept is to think of the pin like a car, you need time to accelerate and hit your maximum velocity. Building that idea you can gain more speed if you travel a greater distance. As for the rods spiraling all over the place, it's kind of because of the aerodynamic nature of rods. They just don't like to fly straight. I've played with some barrel concepts to fix this, but I haven't had much success.
    Also, input is how you get better at k'nex guns, so feel free to ask! We don't bite.
    (When I commented about moving the magazine forward, it reminded me of Dr. R telling me the same thing about my Whaleshark Rifle. Memories sweet memories lol...)

    Thanks for your feedback and advice i will be posting a new turret pistol soon so if you have any feedback on that than please comment when i get it posted.

    Oh and get rid of the layer that "hugs" the middle layer so friction will also be reduced

    1 reply

    So I guess I got tired of waiting for internals so try and use this ammo, it will heavily reduce friction in the mag.

    15, 5:07 PM.jpg
    1 reply

    sorry for not geting the pix i was at an event. That kind of ammo will not fit in my gun it is to big to fit though the barrel but thanks for the info any way!

    Unfortunately, with a band-fed magazine you will have to overcome internal friction between consecutive rounds. One way to overcome this is to introduce a bolt-action system whereby pulling the bolt back primes the firing pin, and pushing it forward loads a round from the magazine into the chamber. For an example, see the ZKAR2 (Instructions used to be on KI, I have no idea where they went). However this will require a large amount of modification to the gun. If you can find a way to reduce magazine friction, this will help.

    Also, as it has been said, removing the barrel will reduce exit friction.

    Something else you could consider is adding more rubber bands to the pin, as long as you can make the gun strong enough.

    1 reply

    Yes i have made the ZKAR and know how it works. i added the barrel to stop the ammo from spinning out of the gun and being vary of target. also thanks for all the tips!

    Looks great, could I get some internals. If I could ill tell you how to get much more range out of it judging by your mech + magazine.