A little about myself, old guy, 77, 10.5 years in US Navy, Vietnam Vet, don't hunt but love to shoot. Trying to get back into long range and was hoping someone could save me a lot of time. I have a 6 and 6.5 Creedmoor and was wondering what seems to be the best weight bullet to use, also on the 6 does it make a difference if you use the small or large primer cases? Don't know a lot about ballistics, going to have to learn. Did get me a chronograph, just got to learn how to use it. Started watching the King of the Mile, You Tube stuff, got me itching again. Any help anyone can give me will be greatly appreciated.