With ammo harder to come by than hens teeth these days I found myself on the phone today for hours to every dealer in Alberta, BC, and started into Saskatchewan before finally finding some 100gr ttsx. There were plenty of 80gr to be had though and I was considering switching (out of neccessity) so I would have enough ammo for my upcoming sheep hunt. When I ran the data on quickload for my rifle (.257 wby) it predicted a velocity of nearly 4000fps which using a 6" point blank would only drop 12.4" at 500yds and 24.5" at 600yds with 100 ft/lb less at the muzzle and about the same at 600yds. Ft/lb are not momentum to be sure but what do you guys think of this set up for sheep/ibex? Marginal/plenty? Definitely not overkill anyway. I did get my 100s but it got me thinking, especially after seeing almost a foot less drop at 600yds. Of course the chance of having to take a shot at that range is slim but I like to plan for the worst. I have shot a goat at 569yds with a .270 and 140gr barnes xbt and can say that is alot of air under the crosshairs at that distance. Any thoughts?