That ammo can has about 300 rounds in it, and the pistol box has the pistol inside. I put them up there to test strength because I was honestly pretty skeptical. Considering that I some how missed the stud completely on the right side, I'd say this is holding up surprisingly well.

I have/had a bunch of different ideas for this, such as not using a back plate and just running the arms straight into the wall studs with the pocket screws. However, with the screws going at an angle, I think it will be too difficult to get a good hit on the stud. Also considered running a support on the right wall, and just notching it, and placing a corresponding block on the bottom side of the top shelf, to slide in the notch, just to keep everything tight. The wall not being at a right angle kind of screws things up, especially since I was going to build 4 shelves, and the wall is at a different angle at each shelf. Open to ideas and suggestions. The idea when this is completed is for everything to fit flush so it just looks like a fancy floating shelf when done.

Finally, here are the various images that gave me the idea.