Whether you cosplay or just like something radioactive for your shelf, this prop may be for you. I've seen a lot of 3D printed ones, but some of us don't have the ability to use a 3D printer. This prop is pretty light since it is mostly EVA foam and it will only set you back around $15 if you already have the basic tools. I didn't use any scaling or measurements from the game, but I used real gun measurements as an equivalent.

Step 1: Materials

The following are the materials you need, I'll make a list of optional stuff at the bottom.

Scrap EVA foam
PVC pipe (2 sizes, one should fit into the other)
One sheet of craft foam (usually comes in packs of 4 or 12 sheets)
Small screws
Wire (I used aluminum wire)
Dremel or rotary tool (sanding drums, pointed sanding stone tips)
Exacto knife or razor
Ruler (kinda optional, but it is pretty important regardless)
Ink pen or marker
Scissors
Hot glue gun and glue
Wooden dowel
Mod Podge (Elmer's glue or "school glue" works)
Acrylic paints (Black, Burnt umber, Brown, Metallic Silver and Orange)

Optional

Rusted Nails
Two inch bolt

Step 2: Barrel and Forearm

The barrel is made from the smaller piece of pipe, It should be about 4 and a half inches long. The wooden part of the gun that the barrel sits in should be just over 4 inches long. The main part that the barrel sits in is 2 pieces, one is about a half inch wide and the other is about an inch wide. Glue the 2 pieces together like a right angle, or an L looking at it from the front. Now you can inlet the foam for the barrel to sit inside it, use a sanding drum to run the length of the foam pieces making a channel big enough that the barrel sits snug. Toward the back of the barrel should be a small cut that is fairly oval. It is just under half an inch long, you can cut it out or use the sanding drum to make it. Once this hole is cut, you can glue in the barrel so that a little is sticking out the back of the foam and some off the front. More should hang off the front than the back. Next cut 2 more pieces of foam. one is nearly the length of the long piece under the barrel and the other is about 3/8s the length of the long flat piece. Cut an angle at the back of both pieces and glue them underneath as shown. Use the dremel to even all the sides up and make it smooth, don't worry about the seams where there is glue. Once it's cooled down, use the dremel to cut in wood grain in the same direction as the glue seams. This will hide them later on. Cut a piece of dowel about an inch shorter than the barrel and put inside to show through the cut we made. In the game it looks to be a small spring around this piece so if you want, wrap some wire around it first before gluing.

Step 3: Receiver Box

This piece is very easy to do. Cut one square around the size of the far end of the barrel/forearm section. That step is shown in the first picture. You'll need a slightly longer one, but the same width. take the larger piece of pipe, about 3 inches long and cut the foam to slide over it. the longer piece goes in the front and the shorter piece goes in the back. slide the pipe with squares onto the barrel/forearm and glue in place. Make sure the squares are even still. Take some craft foam and skin the box. Now you can cut the detail piece. This is supposed to be the bolt action of the gun or something close. I'm actually not sure how it is supposed to work in the game as it is a game and I can't take it apart and look. It is an L shape, but the horizontal piece is thicker and will have a slot cut in it, almost like the one in the barrel. Screws are added to this part, I used a pointed dremel tip to start the holes. Add a piece of foam or a bolt to the bottom of the receiver box for the trigger. In the game it is a bolt, but I wanted something a little more flexible. The rear sight goes on top of the receiver box, it is made from a piece of EVA foam that has been heated and bent into an L shape with the short side sticking up. I dremeled a notch into it, once the front sight is on you should be able to line these up. I made some small "rivets" on the rear sight base with the pointed dremel tip.

Step 4: Pistol Grip

This is a very odd shape. I cut a strip of foam about a half inch wide and 10-12 inches long. I cut v's into the foam where I wanted sharp angles and I used a lighter to heat and shape the rest, that also strengthens it. The 2 ends need to be cut to slide over the pipe sticking out of the reciever. I made the mistake of not leaving myself enough room and I had to add a foam spacer. Once you slide it on, glue it into place and then cut a octagonal piece like a nut. This foam piece will be the cap that goes over the back of the vertical piece as shown. You can detail it with the dremel. Now you can cut some craft foam to wrap around the handle, this is meant to replicate black tape. I added a brace in the middle of the handle to make it stronger and hid it with the craft foam.

Step 5: Forearm Details

Just in front of the slot in the barrel I cut a little channel and glued in a piece of dowel. The second part of this is also an odd shape, but you can look at the pictures for an idea of it. There's a long piece that sits under the dowel and a piece that will have 2 screws in it. I don't know what it's meant to do in the game, but it looks neat. There's also the little "magazine" that sits underneath the slot, its just a piece of foam with dremeled sides and some faux rivet holes. You can add the front sight now. It is a little strip of craft foam on the outside of the forearm with a small length of foam on top of it.

Step 6: Seal the Foam

This step consists of painting on a few layers of mod podge or glue to seal the foam for painting. Make sure to do at least 2 thin coats of mod podge and to cover everything, including screws. Allow it to dry before painting.

Step 7: First Coat of Paint.

This is the easy layer and you can stop after this if you want. Paint all the "metal" parts black and paint the wooden part of the forearm in different shades of brown to make the wood grain show.

Step 8: Drybrushing

Lightly drybrush some metallic silver onto the "metal" parts to add some depth and make the details show. I have an Instructable on wood grain and drybrushing here >> https://www.instructables.com/id/Special-Effects-Pa...

Step 9: Optional: Rust

Take some rusted nails and shake them in a cup to remove rust, you'll end up with a powdered rust. I brushed some mod podge onto the gun in places where I wanted rust to be and then sprinkled the rust onto it. Rust often runs off of screws so put some underneath them. I also added some orange and brown paint to make a grimy look to the metal.

Step 10: Wire

The wire is wrapped around the barrel and forearm toward the front. In the game it is behind the front sight, but I did it just in front of it. You can add a little brown to it for a rust effect.

Step 11: The End

Have fun, but be careful and obey all weapon laws. Some conventions allow prop weapons, but some don't so be super careful. At this point you can go back and paint the strip around the handle black to pull off a black tape look and you can add some silver to the small slot in the barrel. In the game this can be modified in a billion ways so if you make one like I did then add something to it (optics, stock, bayonet) and drop a picture below. P.S. I know the handle it thick.