Everyone thought I was done with the original NES. What could I possibly do after making the world’s largest and smallest controllers? Well, here it is: the world’s only Duck Hunt sniper rifle.

First you will need to pick up a few items:

3 original NES guns
1 Airsoft Super 9 rifle
1 piece of ¾ PVC pipe
1 556 Chip
2 100k-¼ volt resistors
1 Blank Circuit board (Or better yet read my article on how to make your own.)
2 Toggle Switches

If you look inside the original Zapper, you will notice an assembly with a metal cover and some wires running to it. We will need to cut away the cover and pull the connector off. This is the main assembly for our new light gun.

We will need to note three points on the board:

Power, which is the white wire from the connector
Ground, Labeled “R” on the top of the board
Trigger, “B” on the board

The power will be used to supply voltage to the 556 IC chip and the ground is for all the switches and for the chip. The trigger is what we will send a charge to fire the gun.

Looking at the circuit, you might think that it is confusing and wonder why you do it this way. Fear not -- I am happy to explain what is going on here. It is a basic mono-stable flip-flop circuit. Mono-stable means it will hold the circuit in the position that it is currently in until a change is detected. Flip-flop is a type of circuit that means that only one of two switches can be on at any given time. So a mono-stable flip-flop circuit is a set of two switches that when you press the reset switch it will turn on the trigger switch and when you press the trigger switch, it will turn off and wait for you to hit reset.

On the 556 chip we will use the following pins:

Pin 14 is Power (White wire from the Zapper)
Pin 7 is Ground (R on the top of the Zapper board)
Pin 6 is Trigger (Used to turn off power to output)
Pin 5 is Output (B on the top of the Zapper board)
Pin 4 is Reset (Used to turn on power to output)

The resistors are used to hold the state of the circuit at its current position. We can run two resistors from Pin 4 and Pin 6 to Pin 14. This will apply voltage to the trigger and reset that the chip uses to hold its position.

Now that we have the little science lesson out of the way let jump right into the construction of the gun. Let's get started by gutting the gun and getting the trigger assemble apart. After a little work with the rotary tool, you can make room to mount two switches, one facing up and one facing down. The switch facing down is the actual trigger to fire the gun and the switch facing up is used to reset the circuit.

After you have glued the switches to the assembly, you will still need to place the spring to move the trigger back and forth. Then go ahead and run your wires outside the whole assembly and put it back together. Be sure to leave a good amount of extra wire off of the switches so that you can run them to the cartridge chamber.

You might ask the question, How does the reset trigger work? Well, if you look at the bottom of the bolt on the gun, there is an opening where the spring is. It was originally used to build up air pressure for the gun, but we will use it to reset the circuit. When the bolt passes over the switch it closes and when you return the bolt to its cocked position the switch will open back up.

Now let's assemble the barrel for the gun. Take a piece of ¾ PVC pipe and cut it down the middle. This is where we will mount the guts of the zapper as well as our lens assembly.

Do not use super glue to assemble the barrel since the fumes of the glue will cloud the lens. (I learned this the hard way and three light guns later.) I used hot glue since it will not damage the circuit board and it is fairly easy to work with. Now let's mount the Zapper board with out three wires already soldered to it in the barrel.

Measuring from the photodiode (the photodiode is the little sensor at the front of the gun) to the first lens should be 4 inches. I harvested the lenses from three zappers for my barrel assembly. This is not so you can be three times further away but it is used to pass the light through the barrel all the way back to the sensor. Now measure 4 inches from your first lens and place your second lens; and 4 inches from that lens, mount your third lens, and so on. Be sure to leave at least 1 to 4 inches from your last lens to the end of the barrel so that you will not have light interference. I went ahead and placed the weights from the Zapper guns in the barrel to help give me some more weight to the whole gun.

After we use a rotary tool to make room to set the barrel on the gun and hot glue it in place, we can put the top on the barrel and fill the seams in with more hot glue. Be sure to run all your wires ahead of time because you wont be getting back into the barrel anytime soon. Using sandpaper to smooth everything out and some auto body filler to shape the rest of the assembly, we can move into the final wiring.

Running the wire from the barrel, switches and LED down to the cartridge chamber and the controller cable up to the barrel we can call this project almost done.

All that is left is to clean everything up with sandpaper and paint the gun.

Happy Duck Hunting!