Well the photos worked so I'll go on with the description. The opening is 2' x 2' and the material is 1/4" mild steel plate. I was given a 4' x 6' drop from one of our jobs and I was able to cut the main body of the trap from that with enough left over to make the 2 45° (thanks Angie!) deflector plates. I did have to splice the top plate to get it all from the piece I had. The legs are pipe, 1 1/4" if I remember, with the front 2 being adjustable and the rear made in 2 pieces of different lengths. The catcher assembly was made from a hunk of rectangular tubing, a piece of pipe and some scrap plate. The bottom cover is held by 2 bolts and can be swiveled or removed to empty it. The target frame is an old realtor's sign and I cut cardboard to fit.
The trap works very well capturing nearly 100% of the projectiles. Ocasionally I do find a bullet laying on the ground in front of it and sometimes see small flakes of lead under the target frame. No bullet has been found more than 3' from the opening so ricochets aren't a problem. The secret is the angle of the sides. Bullets strike and slide toward the opening as you will see from the photo. With a shallow angle (45° is far too steep) very little of the bullet's impact energy is transmitted to the plate. For those who don't believe 1/4" mild plate will stand up I have fired Hornady XTPs (jacketed hollow points) into it driven by a hot .44 mag handload fired from a 20" barrel from 25 yards without making a mark in the plate. It works well with any form of bullet or round ball I have tried so far. My intention was to have built a larger one, a 4' x 4' opening, from 1/2" plate but my job and the company I worked for went the way of the dodo so it'll probably never happen.