HEY TEXAS,Bricks? I don't see any. That duct seal looks like tar.Hal
For 10 yards or less, I use a duct seal lined pellet trap. One you can buy or build. For 25 yards or more, I use 3/4" pressboard sheet cut in half and doubled. I screw them together. That gives me plenty of room to attach several targets to prevent shooting out just the center, which could happen rather quickly. After it starts chipping away too much, I simply turn it around and shoot a few thousand more rounds. My backstop has lasted almost 2 years now. I use a 2 wheel dolly to roll it out and back into my shop between shooting sessions.I also have a new 4 level target rack but haven't had a chance to actually season it yet. SOON!!!!Has 7 of the practice golf balls on dowels when completely filled up.SAFE & Happy Shooting!!!!Dave