I have a load for my little Ruger Hawkeye SS with Federal factory 338F ,once fired brass, and 52gr of TAC and BR2 primer for a tad over 3000K! I called and spoke with a Barnes Bullets Tech today and he told me I was good to go with this combo on elk, even out to 600yds! ha Well, that's about twice as far as I would ever lob a shot on one, but he did say I could hold dead center of the shoulder at this speed. I know most folks use heavier bullets and I even asked about the 185TSx, but he said I "was good to go" as I am! I like that as I hunted with a 338 Win Mag for years and this little M77 is much lighter, more responsive and far easier to shoot! It should make a good companion to my 35 Whelen AI for elk hunts. I've killed a lot of game with Barnes bullets, from .22 through 35 caliber ( 375 if you consider the same principle with win Failsafe's) I feel real confident with it. That TAC is Jet Fuel!