K'nex Thompson SMG




Introduction: K'nex Thompson SMG

This is my Thompson SMG. Includes true trigger and bottom fed grey connector magazine. Obviously modeled after the Real Thompson SMG used in WW2, this is one of my best shooting guns. It fires dark grey connectors (the one-way kind) and gets about twice the range of my TMG (my side-arm). It holds over 10 shots comfortably, you could get 15+. Other than the magazine which has been used by just about everyone, everything on this gun is made by me. PS - Follow the sticky notes throughout the instructable to get through the tricky spots.


- Good range
- Fast firing (cock, fire, repeat)
- Good looks
- Small and compact


- A little bit flimsy in some spots, but nothing huge
- Inconsistant range, i.e. 1 shot goes 30 ft, next goes 40 ft, next goes 35 ft, etc.

Step 1: Stock

Let's go right into building. This is the stock, made straight instead of the weird angle in the real fire-arm to give it more strength. This is a very simple step.

Pic 1 - Just make exactly what you see (the first layer) 3 times and connect them with white rods. It should be 3 layers thick

Step 2: Rear Portion of the Barrel

This aligns the ram rod, and most importantly contains the ram blocker.

Pic 1 - The finished product

Now start building...

Pic 2 - Left side view
Pic 3 - Top view
Pic 4 - Right side view
Pic 5 - Bottom view

Now make the sights...

Pic 6 - Easy, make it
Pic 7 - Attach it like so...
Pic 8 - And so

Step 3: Handle + Trigger

A strange trigger design, but effective.

Pic 1 - Make both these parts
Pic 2 - Attach them
Pic 3 - This is the handle and all the layers are the same except for the middle one...
Pic 4 - ...Which has a 2 way grey connector as seen in the picture
Pic 5 - Ready to attach the 2 parts
Pic 6 - Attached by both grey connectors
Pic 7 - Another view

Step 4: Barrel System and Magazine

Pic 1 - Make this
Pic 2 - Make each of these x1
Pic 3 - Slide them onto the blue rods
Pic 4 - Next one slides onto the blue rods and clips into the yellow connectors
Pic 5 - Slide on the next one
Pic 6 - Magazine
Pic 7 - Different view
Pic 8 - Build these (Very difficult)
Pic 9 - Attach them onto the mag as follows
Pic 10 - Attach it onto the Barrel system
Pic 11 - Clip on that piece I told you about in the yellow box on the 2nd step.

Step 5: Front End and Front Sight

The first time I saved this, the next page didn't open so now I have to re-do it! Has that happened to anyone before? Anyways...

Pic 1 - Build it
Pic 2 - Another view of Pic 1
Pic 3 - Build it
Pic 4 - Another view of Pic 3
Pic 5 - Attach the 2 together
Pic 6 - Side view of the 2 attached

Step 6: Ram Rod and Mag Push

Probably the hardest step of the whole instructable

Pic 1 - Make them
Pic 2 - other view

Step 7: Assembly + Rubber Bands

Enough with the building, let's attach it all together. I didn't get a piscture of it, but just attach the front barrel and fron sight directly onto the front of barrel and magazine

Pic 1 - Handle + Barrel and magazine
Pic 2 - Attached
Pic 3 - Trigger looks like this
Pic 4 - Rear Barrel + Front Barrel
Pic 5 - Attached
Pic 6 - Attached + Close-up of trigger
Pic 7 - Stock + Rear Barrel
Pic 8 - Attached
Pic 9 - Ram rod goes in
Pic 10 - Ram rod rubber bands
Pic 11 - And they go on like this
Pic 12 - Trigger rubber band - Key to keeping the trigger in place so it doesn't slide off.

Step 8: Loading and Firing

Last Step!

Pic 1 - Put bullets in the bottom of the magazine
Pic 2 - Ram rod goes in like so, and the rubber band also goes like so
Pic 3 - Aim and Fire!

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    209 Discussions


    8 years ago on Introduction

    Not brilliant but not bad at the same time, keep at it :)


    Reply 9 years ago on Introduction

    ive got an instructable on how to make a drum that works for this gun


    Reply 9 years ago on Introduction

    I dont see the 'ible. You must not have posted it yet.


    Reply 9 years ago on Introduction

    oh wow im a moron the drum i made isnt even for THIS thompson.Its for a different thompson and im posting it june 1st


    Reply 9 years ago on Introduction

    it actualy does. theres 3 versions of the tommy, this bieng the one used in World War 2


    Reply 9 years ago on Introduction

    Its still not the best looking tommy gun on this site though.


    8 years ago on Step 4

    It's awesome!...................................Now I understand how to make it!


    9 years ago on Introduction

    wow, TRAUTS this is the first gun ive made by u that actually fires the bullets more than 2 feet! this one shoots 10. IMPRESSIVE!


    10 years ago on Step 5

    Dude just don't make the part of improvise. I hardly ever get to make a full gun


    10 years ago on Step 7

    at first i thought "on no, not another trigger that will always jam" but it works excellent!!!!