This instructable will show you how to build a laser pointer out of an empty 50 caliber rifle bullet. If you don't have a 50 caliber rifle bullet laying around, then go to your nearest gun show and buy one. They usually have some show parts without any powder in them and a spent primer. I don't suggest you start with a fully loaded factory round unless you know how to remove the primer and powder without any accidents. An empty bullet may still have a primer in the bottom, but the center will be dimpled from the firing pin.
Step 1: Remove Lead Tip and Primer
Remove the lead bullet from the empty brass cartridge with a pair of pliers, slowly twisting and pulling outward. Use a cloth in between the plier tips if it starts to dig in.
Push out the spent primer with a punch. you may have to drill it out depending on the construction.
*** Danger***, a loaded cartridge requires special tools to remove the lead and primer without setting it off. Do not use a loaded cartridge.
Step 2: Laser Module
Purchase a laser module with a 1/2 inch outside diameter - don't ask me where to find one - I got mine on ebay. It doesn't matter what color the laser is, I'm using a green one here. The laser module needs to have a removable focus lens.
Step 3: Cut Bullet and Attach to Lens
Cut off the bullet as the diameter reaches the diameter of the threads of the laser lens. Then carefully solder the two together without getting solder into the lens threads or melting the lens if it is plastic. Make sure you drill the tip so the light can get out.
Step 4: Drill and Tap Brass Connection
The laser module is connected to the brass with a threaded set screw. Both the end of the brass and the end of the laser module needs to be drilled and tapped. Be careful not to damage the laser diode while drilling.
Step 5: Add Batteries and Switch
Two "N" cell 1.5VDC batteries fit nicely into the case I used with the laser module I had. You can use small lithium watch batteries also, or a regulated power supply if you'd like. The pushbutton switch I used came out of another laser pointer I had. I just turned down the end on a lathe to fit into the primer pocket.
Step 6: Assemble All the Parts
Assemble the switch, batteries, laser module and focus lens.
Step 7: Have Fun!
Your new 50 cal. laser pointer is now complete. Have fun.