I'll try to answer questions here before they are asked. I couldn't say everything I wanted to say in the video because of the 10min limit.
The suppressors are legally owned by me on a NFA gun trust. And yes it is legal to shoot in my backyard in my county. The backstop is 3" plywood form that holds over a foot of dirt and rubber mulch in front of it to catch the bullets. This stops everything from 22, 9mm, and 45acp.
This combo is very quiet in person, the camera microphone tries to level all the audio and as such will amplify the report of the shot. not to mention you can hear the slug slam into the berm. *Legal in 39states!