Noise aside, more important is the 50 cal. being fired into an adequate backstop? 20 acres is not near enough space to be safely firing a 50 cal. without an adequate backstop. Considering the range of a 50 cal, a much larger area might be required. As I recall, a section of land is 640 acres which is 1 square mile and that is far from adequate space to be open firing a 50 cal. in. If a sniper can hit targets at 1 1/4 mile, you know that it is probable that that bullet is capable of traveling for up to 2 miles. Just some food for thought.