I've been considering joining a local IDPA chapter and try doing some competitions. To be able to practice often and save a little money, I've been picking up a few co2 powered pistols lately that are close in size to my real guns.
I decide to start building a BB trap tonight in the back of the shop, which I wanted to be able to hang three full sized IDPA targets side by side for practice drills. This is the main box, which is 4' X 8' X 20". It will have a few layers of heavy cloth hanging from rods above to slow down and stop the BB's. I used a full sheet of osb for the back stop, which has about a 30* angle to it, but hopefully it won't be needed often and the front layers will stop the BB's prior to getting to it. If they do make it that far, I wanted to deflect the BB so it would have to travel another path back through the layers.
Still need to add some deflectors on the sides, top & Bottom which will probably extend those about 6"-8" further and have some straw bales that will be stacked below. I've been pretty good at keeping my shots on target, even at 15 yards, so I doubt I'll need them, but better safe than sorry.