Since it's illegal to discharge a firearm in the city limits I'm seriously thinking of getting a pellet rifle - likely a Ruger AirHawk .177 cal. - to plink in my backyard with. I figure on building a target box outta plywood. Basic box with open front, rear wall sloping 45 degrees or so to deflect the pellets downward.

Here's the question. How thick plywood should I make the back (deflecting) wall out of? The rifle has a nominal muzzle velocity of 1000 ft/sec so I want to make sure I make the back wall out of thick enough material to MAKE SURE nothing escapes.

Any ideas? Tried googling "target box" and "shooting box" to look for plans but no luck. I just don'k know how penetrating a .177 caliber pellet is. I'll be shooting from approx. 20 yards. There will be a wood privacy fence behind it.

Thanx in advance.

I would not make the deflecting wall out of plywood. I'd use steel plate. 3/16" or 1/4" would probably be plenty thick for an air rifle.

Get some ballistic foam.

I use an old phone book at least 1.5" thick attached to the inside of a box and put the target on the front of the box.. When you are nearly done shooting through it, replace it with a new one.

Ranb

You want to get several pounds of duct seal from Home Depot. It comes in one-pound bars and is made by an outfit called Gardner Bender. Don't let them try to sell you the stuff in the tub. It has to be the GB in the one-pound blocks. This stuff does not dry out over time, so you can dig out the lumps of pellets that form in it and then reshape and reinstall. This is what comes in all the professional pellet traps, and the neat thing is it is silent when the pellets strike.

A moving blanket folded a few times works well, also.

Quiet, cheap, adaptable, you get the picture.

Make sure you don't have neighbor problems. Some state laws, and city ordinances do not allow "spring-powered" guns either. In Florida the state law is written to include pellet guns too.

I use a 10mm steel plate bolted to a wall. Pellets ALWAYS disintegrate on impact with my springer upto 25m.

I like the idea about the bar clay... no noise , no ricochets, weather proof, and very easy to make yourself!

I made one out of 2x4's with a plywood back and filled it with duck seal compound. It's cheap, quiet and the duck seal compound lasts a long time.

The metal backstops are very noisy and they are messy, the lead doesn't stay in the trap.

Thanks for the good discussion, all. MidwayUSA has a trap for under $20, under $30 shipped. I checked w local "Only Ones" PD and confirmed OK to discharge either CO2 or spring so long as it's not a firearm.

I do like the duct seal idea. Gotta look into it. No one would even know I was even doing it. Spring guns are very quiet.

Metal stops make additional sounds, a lead sheet 1/2" backstop stops that problem, you just need a good fence post to hold it

Be careful with the commercially available metal .22LR bullet traps indoors! High velocity pellets shatter and send out a cloud of LEAD! You can actually see the 'smoke' from the shattered pellets as they strike.

If you plan to shoot ANYTHING inside....... have adequate ventilation!

A couple of layers of mine conveyor belt will work, and help dampen the impact sound. But finding some in your area may prove problematic.

Geez guys, I don't know what velocities you are shooting but for my Walther target airpistol I use a cereal box filled with folded newspapers. I shot at 21 feet with no penetration through the box at all.
Peter.