I made mine out of 2 pieces of 15" wide x 5ft long 1/4" steelplates. I had these made at a small weld shop. I had them put 6 holes in each plate so i could screw them to 4x4's -1 4x4 near each end of plates and 1 4x4 down the middle. I first scrwed the plates unto the 3 4x4's with special round headed laag screws that were coated for the new pre treated wood (it eats away other screws)
After I cut the ends of the 4x4's sothey would rest on the top girder at a 45 degree angle, I had to lift the whole contraption up and drag it down to where the trap was going to be. Man it was HEAVY.
I dug out holes with steel bar and post holedigger for the 4 main vertical posts alson4x4's then I attached the double 2x girder. I had to get a comealong to pull the steel plate structure up on the girder. I put 2x's on the angled back side below the plates so I could shovel sand agaisnt it I put a corrugated tin roof over it.
In front I have hinges that i atach pieceof plywood for targets. Above and out from that i have another 2x so i can hang fun targets like rotten apples,tomatoes, water ballons whathaveyou for just plinking.
I shoveled a ton of sand in under the plates. its about 18 inches deep.
The actual plywood target area in front of the plates is 1'x10" nethorizontal projection x 5 ft long.
I havent even tried it out yet but will soon.
I will mostly shoot 38 special and 22's. I may try 357 mag and other calibers and see how it holds up. Every year or so,I will sift out all the leadwith a sieve and recycle it.
I wont use for rifles at least not high powered rifles-Its mostly forhandguns and 22 rifles.
Im not sure how well 1/4" plate would hold up to 44 mags or 357 mags.
I will shoot from 10 yards to about 50 yards. When the plywood target holder gets shot up real bad I will take it off and replace with another.
Now I am thinking about ways I can deaden the sound by maybe using rock wool or homosote or some sound absorbing material around the trap and around a portable/movable shooting bench. I would like to minimize the noise level as much as possible.