Jurassic Park Tranqualizer Rifle

My five-year-old is in a pretty intense dinosaur phase. As a consequence, this Halloween he declared that he would be either "Owen Grady" or "Owen Grady's Partner." He already had the basic clothes and a vest (and bonus dinosaur hat). He insisted he needed a gun to distinguish this costume apart from his everyday wear.

We are a house divided on the issue of toy guys, so our compromise was that rather than the Marlin Model 1895SBL (Owen Grady's rifle), he would go with the classic non-lethal Jurassic Park Tranquilizer Rifle, which Owen does use on occasion. Or, perhaps, no gun at all.

Then, of course, the day before our first Halloween event, I found myself scrambling for what I had around the house to make a tranquilizer rifle.

Is this perfect? No

Is this exactly like the movie? Also no.

Is this something an average person can knock out cheaply in a few hours? Yes.

Does it pass the five-year-old inspection? Absolutely yes.

With a few extra hours to get details right, you could make it look even better. I was under pretty intense time restrictions so my mantra for this project was "Done, not perfect."

I've scanned my basic little sketch/supply list. It's not exactly what got built, but you get the idea. Ultimately, your specific design will depend on what water gun you have.

Materials

1. Water Gun
2. 1/2 inch PVC pipe
3. Glue Sticks
4. Wire (I used bread bag twist ties because I couldn't find my floral wire.)
5. Green spray paint
6. Black spray paint
7. Masking Tape
8. Cardboard (I used a box that was sturdy, smooth and on the thinner side)
9. Plastic Bottle

Tools

1. Drill
2. Glue Gun
3. Saw (or something to cut PVC)
4. Bone folder (this is totally unnecessary, I just happened to have one. You could use the back of a butter knife. It just helps to make fold lines in the cardboard)
5. Boxcutter
6. Cutting Mat
7. Metal Ruler (for cutting straight lines)
8. Pencil/pen for basic sketching

Choose Water Gun

Before anything, I'd like to point out that you could use almost any water gun with a basic gun shape. I really just used it as a way to get out of making a trigger, which seemed like too much work. Your experience will be shaped by whatever water gun you have available. Here are some basic things I learned:

1. Different colors/types of plastic behave dramatically differently when cut. In my case, the orange tip was sliceable with a box cutter. I was afraid I would shatter the white plastic with a box cutter, so I drilled little holes with a drill.
2. Don't try to cut plastic with a spade drill bit. (I initially had the idea I could just get a spade bit and drill a perfectly round hole. Upon reflection, this was a stupid idea.)

Attach PVC Tube Stock

The stock of the gun needs to be as solid as possible because it will probably take the most abuse. Rather than put the PVC through the pistol grip, I attached it to the bottom with wire through drilled holes and hot glue. I felt like this was more secure than drilling a hole. I made a few more drill holes than I needed so I had options to thread the wire. I also flattened the top two inches of the PVC pipe by cutting a bit off. This provided a flat surface and was easier to thread wire through. Once I have the whole thing somewhat securely wired together, I added a ton of hot glue and twisted the wires tight. It seems very sturdy.

I've provided several pictures of my (very inelegant) process. In the end, it all gets covered with cardboard, so glue away and make it as solid as possible.

Attached PVC Barrel

This went super smoothly. I fit the tube through the front and through as much of the gun as I could. I was lucky and the barrel of my water gun was nearly the perfect size. I cut the opening as snugly as possible. I then secured it with hot glue through the water hole.

I wish there was a way to make plans and share them, but this part will be very specific to your gun. I took several pictures of my process and will describe it here, in the order I assembled it.

I kept this all to one box, and I tried to work with the folds and cuts that were in the cardboard as much as possible. It's critical that you use something to keep your angles straight. This was easy with the cutting mat and a metal ruler. Take your time on this step! I nearly cut off the tip of my finger in a rush, which made the process take longer. I blame all typos on this.

Where there are folds, score the parts to be folded and/or trace over them with the bone folder for a crisp fold.

(1) Upper Receiver/Handguard

I traced the gun and then roughly sketched out the length and shape of the main long thin rectangle box. This goes from the top of the gun to about the middle of the barrel. Once I dry-fitted everything, I glue it down.

(2) Scope Mount and Scope

This is one of the parts I would have spent more time on if I had it, but my version was just a simple small rectangle box with a piece of the PVC sanded and glued to the top.

(3) Back of the Gun

I didn't cut the larger rectangle perfectly, so I made a slightly smaller one to fit it over the back of the water gun to make it square. I think it looks cleaner this way.

(4) Barrel Joint and Grip

I made a little L-shaped box to fit around the joint, and cut an insert to simulate pistol grips and smooth out the profile of the hinge. This is another area that done was better than perfect.

(5) Butt/Heel with Plastic Bottle "CO2 Cartridge"

Another L-Shaped box, with a plastic bottle glued on top. Jurassic Park fans might notice that this is actually a triangle in the real version. I was bleeding pretty badly at this point and my finger wrap was really bulky, so I opted for a rectangle. My son has not noticed yet. You can do it better if you'd like.

(6) Magazine

Another small box. Very easy. I have warned my son not to pick it up by this part. It's held fine so far.

(7) Various Bits

At the end, I made small pieces to cover any exposed areas.

I started with black, the used masking tape and plastic bags (not pictured) to cover the black parts and painted it green.

And that's it!

I hope this helps someone throw together an easy prop for another Jurassic Park costume!