Target shooting with a pellet gun is an enjoyable hobby and a fine way to teach kids about gun safety. One important aspect of safe shooting is a target holder that traps the pellets, preventing them from ricocheting. Commercial pellet traps are available, but it is not difficult to build your own. Some traps use a metal plate to deflect the pellet into a collection area; these can be quite noisy and may produce lead dust from shattered pellets. Another design, called a silent pellet trap, safely stops and holds the pellets in a ballistic gel.
Choose a box sized to support the targets you will be using. A large metal electrical junction box will hold a letter-sized 8.5-by-11-inch target (many targets are available on the Internet for you to print out -- see Resources). If you are using smaller targets, choose an appropriate size box. Make sure the box is at least 4 inches deep to hold the duct seal. A wooden box of the correct size will work just as well. Note that many new electrical junction boxes are made of plastic; these will not hold up to pellet strikes and should not be used.
Purchase enough electrical duct seal to fill the back of the box to a depth of 2 inches or more. Electrical duct seal, also called PUG seal, is a dark grey flexible putty used to seal irregular openings in structures and foundations. It will not harden, shrink or stain. It is sold in 0.454kg. blocks; it will take about 3.63kg. to fill a box large enough for letter-sized targets.
Fill the back of the box with the electrical duct seal. A 2-inch depth will handle .22 calibre wad-cutter pellets with a muzzle velocity of up to 700 feet per second. The same pellets at 1,000 fps require 4 inches of putty. Add 50 per cent more putty if you are using pointed pellets. Smooth the putty evenly over the back of the box.
Trim the cardboard to just cover the front of the box and tape it in place. Tape a target onto the cardboard. Place the assembled pellet trap in a location with a solid backstop such as a fence or hillside. You are now ready to enjoy safe target shooting.
After many weeks of shooting, simply pry the excess pellets off of the duct seal and smooth it over. It will last almost indefinitely.
If you are using a high-powered pellet gun, add MDF particleboard to the back of the box before layering in the electrical duct seal for extra strength.