Introduction: CM-10, the Mech of a Bolt-action Sling-shot Rifle

I had decided to make a k'nex slingshot rifle with a removable magazine, and by doing that i needed to find a way to load a single round into the rifle at a time, without making it semiautomatic. Which meant the rifle needed a bolt which is what i designed. I am only posting the mech because i had to disassemble the barrel, stock, and trigger to work on another rifle, so, the barrel, stock, and trigger are up to you guys, post pictures and ill add them on the last step of this instructable so other people can get ideas. 

 - Quick reload (for a slingshot rifle)
 - Removable magazine (with no broken knex)
 - Wider body for more stability (depending on rubber-bands)
 - The mech has to have a correct contrast of rubber-bands to work well. 

Step 1: Magazine

Picture of Magazine

The magazine of the gun, the rubber bands on the magazine slide should be smaller then average, but should be able to push the slide up until you can see the blue, green, and red connectors...

Step 2: Internals, and a Single External Panel

Picture of Internals, and a Single External Panel

Majority of the internal mech and one side panel (clearly), I will explain rubber-band placement and inserting the magazine on the last step.  

Step 3: The Final Panel and Last Pieces of the Mech

Picture of The Final Panel and Last Pieces of the Mech

Rubber-bands and inserting the magazine will be described on the last picture.  


sferrl (author)2012-05-19

how do you load the mag.
i am using yellow rods insted because i dont have enough orange connecters and they are the same length as the regular ammo
but the rods keep falling out and i can make a design that wont prevent the mag from going into the gun (im using my own gun design, if it works ill post it)

Knex.X (author)sferrl2013-02-03

The rubberbands catch upon the connector ends to shoot, yellow rods don't work.

PotatoCoffee (author)2011-11-30

Meh' make the barrel longer, and the mag. The bigger the better.

Ukiarue (author)PotatoCoffee2011-12-17

barrel length depends on your bands, i was using surgical tubing that was cut to fit that barrel... you could make the magazine longer, i dont feel like i need to though, i would need to adjust other rubberbands on the mech... i could improve the magazine design except ive had the gun apart for a long time now, probably not going to put it back together any time soon lol

PotatoCoffee (author)Ukiarue2011-12-18


verypoopy (author)2011-06-22

I'm really interested in this mech but I don't quite understand it. Could you please explain it more or take a few pics so I could understand it more? I've been trying to make a mech for a while and i think this is it. I'd really appreciate it.

Ukiarue (author)verypoopy2011-06-22

i have a video of it for one of my instructables, if that doesnt help just post another comment and ill see if i can help

verypoopy (author)Ukiarue2011-06-27

Oh i understand now. It's less complicated then i thought. I was trying to make it so when you pull the bolt back it cocks the firing ram (different firing mech than what you have on this gun) and loads the bullet in the chamber like you made. This is cool,

Ukiarue (author)verypoopy2011-06-27

i see where your coming from, and thanks lol...if you can manage a mech like that go ahead and post man, sounds unique

ttrimmer1 (author)2011-06-07

i need to know how to make the triger barrel and the stock please

Ukiarue (author)ttrimmer12011-06-11

its a sling shot style rifle, so make the barrel in comparison to your bands, for the trigger mech make a simple ratchet, and just throw together a nice looking can just look stuff up, i didnt feel like including the other things because if ound them easy to make, sorry for the late response.

~KnexBuild~ (author)2011-05-20

how many yellow connectors are used

Ukiarue (author)~KnexBuild~2011-06-01

no idea, not too many for the mech still need to make a barrel, grip/trigger, and stock if your into that, sorry for the late response

~KnexBuild~ (author)Ukiarue2011-06-07

I made the mech then i made the other mech (i broke it though)

~KnexBuild~ (author)2011-05-20

awesome bolt design

sixtyjackman (author)2011-02-10

where is the firing pin ? im confuzled :/

thats where the words sling-shot come in handy ;)

mahmel (author)2011-02-20

Pure awesomeness! 5* and a sub! I've searched and tried such a mech for months!

sixtyjackman (author)2011-02-10

forget that last comment but :
1. how do you keep the ammo in the mag
2. when the mag is inserted, the ammo doesnt quite reach where the bolt is.

Ukiarue (author)sixtyjackman2011-02-10

i didnt see this comment sorry lol, what do you mean by keep the ammo in the mag? and if you use some stronger rubber bands maybe? the way i had the design i had to push up on the magazine ...bullet pusher thing the last shot or two ...

Mac1997 (author)2010-08-14

i just finished it in 1 hour very simple gun but good

Ukiarue (author)Mac19972010-08-14

thanks, did you make the entire body? if you did you should post pics :P

osi (author)2010-07-17

Hmm... I wonder if I would be able to put a semi auto rubber band gun mech on it... to make it bolt action without having to re-pull the band every time... I'm gonna do that... sometime...

Ukiarue (author)osi2010-07-17

do it, and let me know how it is, it should give it a bit more range i would think because of less friction on the bullet. nice idea by the way

anres321 (author)2010-07-15

hey, I have made a knex shotgun with a pump-action systen. you can reload very fast and easy !! the magazine holds 20 rounds and you can shoot them all in less than 40 seconds !! the gun is also very powerfull. plz tell me what you think about it.

Raikou-san (author)anres3212010-07-16


dansdoc (author)2010-07-14

dont know how to rate or subscribe im knew

Ukiarue (author)dansdoc2010-07-14

when your at the top of someones instructable page, it should be on the right, below the advertisement, it will show rating, picture of the author, say some other information, click the stars to rate, you can always change your rating, and to subscribe click the big yellow subscribe button in the same area lol

dansdoc (author)Ukiarue2010-07-14


Ukiarue (author)dansdoc2010-07-14

no problem

dansdoc (author)2010-07-14

can i just doa normal rachet not oversized

Ukiarue (author)dansdoc2010-07-14

i would make it wider if your using biger bands, if not then dont worry about it.

dansdoc (author)2010-07-13

can i at least have instructions for bipod and the barrel uses up to many yellows so ill substitute ps for mech can i do some yellow and some blue? pps or pss its awesome

Ukiarue (author)dansdoc2010-07-13 that's the bi pod i used, and yes you can substitute all of the yellow rods in the mech and use blue rods, and thanks again, you should rate it if you havnt :P

dansdoc (author)Ukiarue2010-07-14

no i mean could you have half yelow rods and half blue?

Ukiarue (author)dansdoc2010-07-14

yeah you can

dansdoc (author)2010-07-12

you should post the rest of the gun soon

Ukiarue (author)dansdoc2010-07-12

you can probably make the barrel from either the video i have or picture on here, and the trigger was just a simple ratchet system that was two wide, and the stock sucked lol.. the barrel however, don;t make the same tip i had, make something that's smooth with the barrel... i got 150 ft with a different barrel design and sniper round, im pretty sure it could of gone farther but it hit shrubbery lol

dansdoc (author)2010-07-10

this is awesome!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :-{)

Ukiarue (author)dansdoc2010-07-10

did you make it? lol

dansdoc (author)Ukiarue2010-07-11

yes its totally awesome!

Ukiarue (author)dansdoc2010-07-11

lol thanks

Fred the Penguin (author)2010-07-09

this is pretty damn good.

Ukiarue (author)Fred the Penguin2010-07-09


~KGB~ (author)2010-07-08

make the whole gun again, great mech! 5*

Ukiarue (author)~KGB~2010-07-08

need pieces >_<

~KGB~ (author)Ukiarue2010-07-09

buy some... lol!

dansdoc (author)2010-07-09


Mr. Muggle (author)2010-07-08

is this the entire gun? It actually looks like this is just the middle part or something like that....

Ukiarue (author)Mr. Muggle2010-07-08

You are right, this is only the middle part, in the intro i stated that i had to disassemble the stock, barrel and trigger, did the title confuse you/is there a way to change the title? lol

About This Instructable




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