K'nex MP5




Introduction: K'nex MP5

TGKT entry - This is my K'nex MP5 and one of my favourite real-life weapons of all time. It features a true trigger, 15+ round mag, full stock, and a rugged construction. The gun has yet to misfire (the bullet always leaves the barrel) and has fair range (30-45 ft).

In the instructable there is no assembly step as I assemble it as you build each main part. Follow sticky notes for the tricky spots before asking questions.


-Small,compact, and sturdy
-True trigger
-Large magazine capacity
-Good range
-Consistant accuracy


-Not good for long range shots

Step 1: Magazine and Barrel

Pic 1 - Build x2
Pic 2 - Add white rods onto ONE of the two panels made in pic 1
Pic 3 - Another view of pic 2
Pic 4 - Make all of these
Pic 5 - Slide them onto the corresponding rods
Pic 6 - Another view of pic 5
Pic 7 - Attach the red connector here
Pic 8 - Get the second panel ready
Pic 9 - All attached

Step 2: Trigger

Pic 1 - Trigger
Pic 2 - Different view
Pic 3 - Place it in the gun like so (leave it loosely in there for now)

Step 3: Outer Body

Pic 1 - Make this x2
Pic 2 - Attach to both sides
Pic 3 - Attached
Pic 4 - Trigger goes between these yellows

Step 4: Front Barrel

Pic 1 - Make this
Pic 2 - Attach to the front of the gun
Pic 3 - Different view
Pic 4 - yet another view

Step 5: Foregrip and Muzzle

The muzzle functions as a safety for the gun. It will block any bullet fire out. Simply remove when ready to fire.

Pic 1 - Completed Foregrip
Pic 2 - Different view
Pic 3 - Another view
Pic 4 - Yet another view
Pic 5 - Ready to attach
Pic 6 - Attached
Pic 7 - Other side attached
Pic 8 - Build the muzzle
Pic 9 - Attach it
Pic 10 - What you should have so far

Step 6: Handle and Trigger Guard

Pic 1 - Finished product
Pic 2 - Make everything seen here x1
Pic 3 - Attach
Pic 4 - Attach
Pic 5 - Ready to go onto gun
Pic 6 - Trigger guard is attached
Pic 7 - Line up the handle
Pic 8 - Attach
Pic 9 - What you've got so far

Step 7: Stock

A very sturdy, solid stock...

Pic 1 - Finished product
Pic 2 - Make this x2
Pic 3 - Make this x2
Pic 4 - Make this x1
Pic 5 - Make this x1
Pic 6 - Attach blue rods where shown
Pic 7 - Attach layer
Pic 8 - After layer
Pic 9 - After layer
Pic 10 - And this is the last layer
Pic 11 - read note
Pic 12 - read note
Pic 13 - Ready to attach bendy rods
Pic 14 - Attached
Pic 15 - Ready to attach the stock to the rest of the gun
Pic 16 - Attached


Important step... This keeps the ram from pointing down and hitting the magazine parts.

Pic 1 - Pull off this green connector
Pic 2 - As shown here
Pic 3 - As shown here put a green rod inside
Pic 4 - Inside and you're good
Pic 5 - Close it all up and you're great

Step 9: Mag Push, Firing Pin, Rubber Bands

Rubber band placement on the ram rod is key...

Pic 1 - Build and find these items
Pic 2 - This is another mag pushed that works a little better than the weird looking one
Pic 3 - Trigger rubber band (A little bit tighter than normal)
Pic 4 - Mag push goes in here
Pic 5 - Rubber band placement for the mag push
Pic 6 - Ram rod goes in here
Pic 7 - It's in with a little force

  • Pic 8 - Ram rod rubber band. It's on that blue rod I mentiond earlier. You could put it on other places but they have to be pulling from below the level of the ram rod, otherwise it will be levered down and hit the internals of the gun (Very low chance of happening). I advise using the spots provided in the picture and in the sticky notes to avoid problems. I will post a video on this. It's a very small problem (it only happened once) but this is just to avoid that.

Step 10: Loading

Pic 1 - Ammunition
Pic 2 - Load like so

To fire once loaded, pull back the ram untill the trigger clicks, then pull the trigger. Repeat untill ammunition is depleted then do pic 2 procedure and reapeat this procedure.

Pic 3 - Have fun and don't shoot anything unprepared to be shot at

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    279 Discussions


    Question 9 days ago

    Does it have the classic mp5 slap reloading mechanism?


    8 years ago on Introduction

    I have built all 5 of your guns, and when i get my youtube account in another year, i will post them on there. They are awesome guns!


    Reply 7 years ago on Introduction

    I don't think I will post them, but they are awesome guns. :)

    mr. 707
    mr. 707

    8 years ago on Introduction

    i wish that i could build this gun but i dont have enough knex hinges.

    all right. so i built it i cocked it filled up the mag pulled the trigger and it fell out of the barrel. woopie!a gun that shoots 4 inches!! the ball joint end keeps on beking off and the mag rod pushes the bullets in half way then it jams. . Either i suck crap with knex or this gun sucks.:(


    Reply 9 years ago on Introduction

    u probably suck crap with knex1 CAUSE THIS GUN IS AWESOME!


    8 years ago on Introduction

    I had some problems with the trigger but fixed it and made it shoot gray rods


    9 years ago on Introduction

    i made the model perfectly and followed the instructions except the trigger don't work at all is there anouther one i can use in the model to make it work


    11 years ago on Introduction

    I have a problem where the gun somehow shoots multple rounds per shot. Seriously, I loaded it up, cocked it, fired, four rounds came out...


    Reply 11 years ago on Introduction

    that is a defult I guess but if it still shootd strong and straight its makes it like almost full auto