The Knex Thompson Sub Machine Gun (SMG)

About: i am a knex gun builder

This gun is fairly powerful, 30-50 feet with two rubber bands, can hold 4-6 rubber bands, it has a true trigger and is accurate for 20-30 feet. Please post comments and enjoy!


Step 1: Magazine

Make the magazine

oh and the missing black fist connectors at the bottom are supposed to be there, i just ran out of them!

Step 2: The Trigger

Nice, easy true trigger.

Step 3: The Handle

1. Make

it looks unstable but it will be supported by the barrel and the stock. it is very stable.

Step 4: The Barrel Extension (with Forward Sight)

All fairly simple, no need to take apart, to make instructions.

this is the barrel extension and forward sight

Step 5: The Barrel

The Barrel is easy to make and has barely any friction for maximum power, again no need to take apart to make instructions.

Step 6: The Stock

Picture 1:Make.
Picture 3.Join them together.

Step 7: Putting It Together.

1. Add the handle as seen, the black connector goes inbetween the first tan lock and purple connector, then the purple connector to the right goes right inbetween the gap of the handle for extra stabillity.
2. Fairly simple to attach, but the top green part that blocks, i would change it with a Y connector to make shooting a bit better. just if you dont pull the trigger fast enough with the green rod on it will be harder to fire.
3. Add The Magazine, really easy to be honest.
4. Add the extra barrel, easy again
5. Add the stock.
6.Look at the bottom of the handle, there is a grey connector attached near the red, sorry for not telling you but you need one to be there and on the other side.
7.This is the magazine pusher.
8.This is what it should look like
9.It should look like this also.

Step 8: Loading and Firing (attaching the Rubber Bands)

Only one more thing to go..... oh and the firing pin, i forgot, is simply a grey rod with an orange connector at the end with duct tape strengthening it.
1.You'll need this, ignore the grey connectors, i already told you about them!
2.Attach like so on both sides.
3.Draw back to here and hold, (also add the rubber bands to the trigger as shown.
4.The Finished result.
5. Load the mag with white rods, about 10 and put the mag pusher in with a rubber band

Thanks! Please comment and rate. any mods are welcome as long as i get some credit. happy shooting.

Ps. this is my first instructable, sorry if its not the best in the world, like mepains guns....



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    96 Discussions


    4 years ago on Introduction

    I made it it was pretty bad. No offense but totally not how you described it to be


    7 years ago on Introduction

    Firstly, you should try filling it out a little (especially on the stock)
    Secondly, I haven't built it but it doesn't look too sturdy
    You should also make it a bit larger.

    But overall not a bad gun for a replica, looks quite like a Thompson, work on it and it could be alto better. :)


    9 years ago on Introduction

    NONE OF THESE DAMN THOMPSON'S WORK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    10 replies

    Reply 7 years ago on Introduction

    well 1. i built it before i built it right it was not working 2.that was 2 yrs ago and 3i was pissed because i wanted to make a Thompson


    8 years ago on Step 6

    youl need to do some work on the stock..siriously