How I know when a rifle "likes" a particular load? Once zeroed for a given range, the bullets strike exactly on, or very close to, where the sights were on the target when the round fired. At 1000 yards with a .308 Win., I don't want to miss my point of aim no more than 4 to 5 inches so the rifle, ammo with my abilities have to shoot holes in paper no worse than about 9 inches apart at 1000 yards when fired a steady rest. That's for a string of at least 20 shots.
While this may be a surprise to readers, I've only worked up one 1000-yard load for the .308 Win. case. All the others I've used to win or place well in matches at that range have been the same load that lots of folks have used to do the same thing. That's with bullets from 155 to 200 grains.
Therefore, if you'll let me know what bullet you want to use, I can give you a recommendation for a load. It helps a lot for best accuracy if the bullet's a few ten thousandths bigger than the barrel's groove diameter. If you could slug your barrel then carefully measure the slug's diameter, that number will help. Also, the barrel's length and rifling twist rate, too.
Group size in angle does not remain the same all the way down range to a distant target. They tend to open up about 10% for each 100 yards past the first 100; sometimes a lot more. If one wants their stuff to shoot no more than 1 MOA (10 inches) at 1000 yards, it'll have to do no worse than 1/4 to 1/3 inch/MOA at 100 yards.
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master
Last edited by Bart B.; February 2, 2013 at 03:08 PM.