Very simple reason a person would not use a muffler or silencer

There is a very simple reason a person would not use a muffler or silencer while target shooting at a range. They only recently became legal in North Carolina to own one (late 2013) and only for hunting purposes. To obtain one, you must first get the approval of the Federal Bureau of Alcohol, Tobacco, and Firearms, pass a federal background check, pay a federal tax payment of $200, which would then allow you to apply to the county sheriff for permission to own one. Then you have to find a vendor willing to sell you one. As near as I can find, the federal law only allows their use in hunting, not range shooting.