Someone shot into the air or at an animal/target standing at the top of a very steep hill.

This year there was the case of a boyin a school yard at Bray, OK. He was hitwith a .30 caliber bullet apparently fired from a long distance. The bullet had two lands and grooves whichmeans it was most likely fired from 03/03A3 Springfield rifle barrel.

http://mobile.newsok.com/article/3319747/bullet-that-struck-bray-teen-identified