Introduction: Knex Semi-automatic

Picture of Knex Semi-automatic

Or bolt-action, pump-action, or whatever you want to call it. (it loads automatically)
Shoots yellow rods, max. capacity 20. Colors and rubber band tensions vary. Modify as nessesary.

*See below comments; I mistakenly re-posted this in 2009. Please refrain from freaking out.*

Step 1: Get Pieces

Picture of Get Pieces

If you don't have over 200 pieces, you can't make this. These lists do not include the ammo (yellow rods).

*can be substituted for similar pieces

Step 2: Construct Barrel

Picture of Construct Barrel

Step 3: Construct Handle

Picture of Construct Handle

Step 4: Make Trigger

Picture of Make Trigger

This is actually a 2-part trigger, but the first part wa included in the barrel.

Step 5: Assemble Parts

Picture of Assemble Parts

Make sure the handle connects fully to the barrel.

Step 6: Make Firing Pin

Picture of Make Firing Pin

The part in the last picture will go on later.

Step 7: Make Other Parts...

Picture of Make Other Parts...

Step 8: Make Other Parts...

Picture of Make Other Parts...

Step 9: Assemble More Parts...

Picture of Assemble More Parts...

Step 10: Make Automatic Feed

Picture of Make Automatic Feed

Make two of each of these pieces.

Step 11: Make Other Parts...

Picture of Make Other Parts...

Make two of the first piece, and one of the second.

Step 12: Assemble More Parts...

Picture of Assemble More Parts...

Step 13: Attach String and Rubber Bands

Picture of Attach String and Rubber Bands

Step 14: Attach Automatic Feed...

Picture of Attach Automatic Feed...

The rubber band should not be streatched to its fullest; if it is, connect two together instead.

Step 15: Prepare to Fire

Picture of Prepare to Fire

Load ammo, pull back pin until it locks in place, and fire.
If it jams, pull back the pin until it locks. Check that the ammo is in place to be fired, and try again.
If the pin doesn't lock, adjust the rubber band shown in step 13, picture 7.

Note: the more ammo you put inside, the less well it works.


nathan's knex (author)2011-08-21

i made this gun and it looked good but keeped jamming so i had 1 mag and it worked like a drem


smidge147 (author)2008-08-06

we have a thing called forums! GO ADVERTISE THERE! YOU NOOB!

The Jamalam (author)smidge1472008-08-27

and i dont see any guns like mine on your homepage

Just be Quiet pleeeeeeeeease!

i didn't say anything, i typed it.

bounty1012 (author)The Jamalam2009-01-05


The Jamalam (author)bounty10122009-01-06

hehe rofl

zapple (author)The Jamalam2009-06-01

wow, no afence but dont you know its not nice to talk back to people. and plz just go advertise some were other then here. i thing your guns are greate and i biult all of them, but its just not nice. plz respect the author.

the_boss_builder (author)zapple2012-03-18

y shudent people talk back bossy

bounty1012 (author)zapple2009-06-02

Please don't try to correct people when you obviously cannot spell. (Btw I spelled I kno rite wrong below to make it funny.)

The Jamalam (author)zapple2009-06-02

Pointless comment? lol this was january.

bounty1012 (author)The Jamalam2009-06-02

I kno rite? and for some reason I got that message in my inbox.

bounty1012 (author)The Jamalam2009-01-06


smart alack!


The Jamalam (author)smidge1472010-04-16

Oh, the irony... 

The Jamalam (author)smidge1472008-08-07

i am not a noob anymore, and i had been a member for 2 days when i posted that. And i have seen you advertising anyway, so stop talking in 3...2...1...

No one ever talked (yes now I'm being a smart alack)

whats an "alack"?

you mean you are still here? sorta?

Dude Stop advertising your guns here, this is someone else's instructable!!!

If you guys want people to take any of the knex posts seriously, I suggest you act a little more mature, or at least take it to your own instructable.

Puddock (author)2011-12-06

I think you left but, awesome!

mberg (author)2011-05-28

do u always have to pull it back

zmxninja (author)2011-04-13

Someone please kill The Jamalam!!!

Football viking boy (author)2011-03-31

My gun only shot like two feet, but it was still automatic which was cool.

knex twintoe (author)2011-02-06

Nice gun.

Agorion (author)2010-09-10

can you guys look at this and tell me if I should make instructions?

14r31337 (author)2010-08-13

Are the spacers at the bottom rod neccessary? Or are they just there to keep the other two rods from getting too close to each other?

anres321 (author)2010-07-05

hey I have made a fully automatic knex gun that works with a totaly diffirent system that is never used before on a fully automatic one. So would you plz tell me wath you think about it ?? here is the URL:

mikstr2 (author)2010-04-17

your camera has bad quality but in a good way that you can still see it ok... interesting

Miles Tails Prower (author)2009-03-04


dont be mad... he is the god of knex guns. he invented them. i think.

altrobot (author)Millawi Legend2009-05-27

WTF? KILLERK posted the first knex gun, dont argue when you dont know

The Jamalam (author)altrobot2010-04-16


NYPA (author)altrobot2009-10-30

No he did not. He posted the first GOOD first gun.

No it's not!!!! But killerk made the first basic gun. This guy made the first prototype. It's called: "Basic knex cannon". Think before you type.

i found one online at some random website copyright yr 2000!!!!!!!!!!!!!!!!!!!!

if thats a cannon, whats IAC's heavy "cannon"?

Sekiha_tenkyoken (author)chopstx2009-07-20

A big crossbow?

chopstx (author)Sekiha_tenkyoken2009-07-21

no i am saying that if that is a cannon, then IAC's heavy cannon must be a humongosauraus cannon. lol.

Sekiha_tenkyoken (author)chopstx2009-07-23

Oh, okay..

Millawi Legend (author)altrobot2009-06-13 that is the first kne'x gun. you owe me an apology.

DJ Radio (author)altrobot2009-06-08

we know that his gun is not the first. This guy made the first gun (not this one)

Bartboy (author)Millawi Legend2009-07-05

He didn't invent them... he posted one on the internet. The K'nex company invented them long before that.......

yes he did.

cerj (author)SeMi_AuToMaTic2009-05-24

I thought Oodalumps invented semi auto's. What's going on here?

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