Loaded some more 257 Weatherby today, only 21 rounds because that is all the H1000 powder I had. 87 grain Speer Hot Cor, flat base, 77 grains of powder, CCI Bench Rest primers. Supposed to go 3,550 fps, I could have loaded to 80 grains for 3,665
fps, but no real reason to go that hot. The darn gun shoots so flat out to 300-350 yards there is no reason for more speed. Pretty hard to even see a coyote at 300 yards in the sage brush anyway. I will chrono and test them for accuracy and go from there. Love that gun, can't miss with those thangs.
The beauty of those little bullets is that is you see a coyote loping along and you have no clue if you will get the shot at 150 or even 325 yards and you never ever have time to use a range finder or try to guess the range, so you just point at the center of the chest and shoot, you cannot miss out to 325 yards, and if you think he is further, you just hold on the hairline and you are good to about 360 or so.
The longer .257 bullets have much better BC and shoot much flatter, but point blank on a coyote to about 350 yards is more than we need. Far better than the gee whiz rounds like the 6.5 Creedmore and those who drop like a brick after about 325 yards. Love these zippy little guys. Gonna load some hot 243 for my next project.