I own a Ruger M77 MarkII in .280 caliber. It is a really sweet shooting gun. By far the best shooting deer rifle I have ever owned. I usually shoot Winchester Ballistic Silvertip in 140 gr. or the Hornady Light Magnum in 139 gr. Both of these cartridges have almost identical ballistics and groupings with my gun. However I am planning a combo whitetail/elk hunt in Canada this fall and I'm thinking I need to shoot a heavier bullet for the elk(160-165 gr.). As cartridges for this caliber run in the $25-$30/box range, I do not want to have to buy 10 boxes of shells to determine what shoots good in my gun. Has anyone had any experiences with this gun/load combination and what brand seems to work?