Tires actually work a bit like an anechoic chamber because of the shape of the inside of the tires and the density of the rubber. The mass of the tire is what really helps. I'm sure the thicker and heavier the tires the better they will work. I am looking at a new house and hope to install a shooting lane to at least 100 yds. I'm thinking of a pit with a movable table so I can shoot offhand, seated or prone. Probably a berm on either side around most of the shooting position topped with some railroad ties. With the berm and the tires covered in soil, and maybe a few shrubs, it should not have the redneck look at all.
