Introduction: MAR-4

About: I make K'nex guns, specializing in semi-automatic, RBG-Slingshot hybrid systems which i use in most of my guns. Note: I am not responsible in any way for any damage, injury, or death caused by my Instructab...

This is my MAR-4 (Masterdude Assault Rifle version 4). Upon request of fellow members of the K'nexing community here, I have made it using a new firing mechanism (firing pin/ramrod type). It fires my standard ammo, however if you are doing single shot then it will shoot blue rods, and others if you load down the barrel.

-Adjustable sight
-Trigger guard
-Cheek rest
-Removable magazine
-Vertical grip
-Good power
-Can be breech loaded

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Image 1: Gun with optional gear.
Image 2: Gun without optional gear.

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Step 1: Main Body: Components

Make the following as shown in the images. They will be assigned a letter for further reference:

Step 2: Main Body: Construction A

Follow the steps:

Image 1: Add blue rods to Part A.
Image 2: Add Parts B and C, gray connectors, and white rods.
Image 3: Add Parts C, D, E, F, G, H, I, J, and N, and gray connectors.
Image 4: Add Parts C and K, and gray connectors.
Image 5: Add Part L.
Image 6: Add Part M.
Image 7: On other side, add metallic blue clip and gray connectors.

Step 3: Main Body: Construction B

Follow the images:

Images 1-2: Make these.
Image 3: Put them together as shown.
Image 4: Place it as shown.
Image 5: Make this (Ramrod/Firing Pin).
Images 6-12: Make this as shown in the images (images are step by step) (Charging Handle).
Image 13: Place the Ramrod/Firing Pin as shown.
Image 14: Flip red connectors up as shown so they snap into place with the white rod.
Image 15: Place the Charging Handle as shown.
Image 16: Connect the two together as in the image.

Step 4: Magazine

Follow the images:

Images 1-2: Make 2 of each.
Images 3-4: Make 1 of each.
Image 5: Add white rods.
Image 6: Add the other parts as shown.
Image 7: Cover with the last part.

Step 5: Sight

Follow the images:

Images 1-3: Make 1 of each.
Image 4: Make 3.
Image 5: Add blue rods as shown.
Image 6: Add the 4th part, silver spacer, and light gray connector.
Image 7: Add the 1st and 4th parts and a tan clip.
Image 8: Add the 4th part, silver spacer, and light gray connector.
Image 9: Cover with the 3rd part.
Image 10: On other side, add a gray connector.
Image 11: Add a tan clip as shown.
Image 12: And add a small gear.

Step 6: Front Grip and Cheek Rest

Front Grip: First image. Further instructions should not be necessary.

Cheek Rest:
Image 2: Make 2.
Image 3: Make 4.
Image 4: Put them all together using blue rods as shown.

Step 7: RubberBand Placement

Follow the images:

Image 1: Pull the yellow rod to the right.
Image 2: Put rubberband around the blue spacers as shown.
Image 3: Pull rubberband under the ends of the blue rod as shown and hook on the blue spacers on the other side.
Image 4: Push the yellow rod back into the center.

Step 8: Operation

Placing the rubberband as shown in the trigger area (image 3), load the magazine (image 2) with ammo (image 1). Take the magazine and insert it properly into the magazine feed. To cock it pull the charging handle back as shown in images 3 and 4. To load using the side breech, lift the breech up to open up the breech, and then insert the ammo. Then close it by pulling the breech down (images5-7). Then you shoot by pulling the trigger to fire, and pull the charging handle to reload. To aim you can use the sight (image 8). You can adjust it for better accuracy. Proper attachment of optional gear is shown in image 9.

Warning- This may cause harm or injury if misused. Do not point it at people. I am not responsible for damage, injury, or death caused by this instructable. Even with safety engaged it can fire. Always treated it as armed.

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    46 Discussions


    Reply 8 years ago on Introduction

    On the other side there is a flap/breech which can be used to single load the gun. You can see it in the 8th Step.


    Reply 8 years ago on Introduction

    Thanks. SMGs are nice, but bullpup makes them even better. " =) "


    Reply 8 years ago on Introduction

    I like bullpups, but my fav is the F2000 =D I like using smiles XD You should see some of my things.


    Reply 8 years ago on Introduction

    Thanks. I wanted to make something new and more-less practical. Now you can load without removing the mag.


    8 years ago on Introduction

    help! my gun wont cock! it just slips past the trigger! help please!