craig 1985 - I have been using Winchester Ballistic Sivertips in my 7 mm Mag and have never had any issues with keeping it sighted in. A friend of mine has a 300 WSM and he couldn't keep it sighted in and it was his new scope that was the problem.I was using federal, but then switched to winchester. Which is when i started having problems keeping it sighted in. So I am still not sure if it was the bullet or scope, (havn't put enough shots through with the new scope yet). But everyone tells me to stay away from federal and winchester!