I live outside the city limits, and shoot a bit. But, I do have neighbors about a half mile away. Kids that play outside, and such. Not wanting to be more of a dick than I have to be, I built this. 22 and pistols don't carry, but big centerfire can be unnerving to people outside. I have a gokd relationship with my neighbors, they all know I shoot quite a bit, but this still cuts the big noise down quite a bit. I built all of this for free. Buddy gave me the drums which have been cleaned per Osha regs. Carpet came from a rent house that was being removed. Basically that's it, besides screws and such. I cut a "notch" out of one end of each barrel, leaving a good deal of the ends to act as ballfles. I then lined the inside of each with 2 layers of carpet. Stacked the drums, and screwed them together with 2in decking screws. At the joints where the drums came together, I wrapped a few layers of carpet, snd wrapped over that with Duct tape. It works VERY well. You can stand 5ft away from someone firing a centerfire through it, and not need hearing protection. A ton of sound is contained, and the massive BOOM is eliminated. Plan is to set it on saw horses elevated, and in front of my shooting bench. My brother has a Db meter, and I'm going to do some hard # tests with various firearms when he brings it. I'll make a video as well..