why does the U.S. military and police force insist on using a 308 for a sniper rifle if the ballistics on a 7mm Rem Mag. look so much better. More power, flatter trajectory, and more speed. Same thing goes for the 6mm BR and 6.5x284. They are the choice of 1000 yd. competitions, yet a 243 AI has better ballistics. Better being once again, flatter, faster, and more energy. I've chosen a 50gr. bullet for my 22-250 based off of books, and once again people say to go with 55's and 60's. Have I made a mistake?