I just bought a box of the 220g SMK for 1000 yard shooting. They will be worked up in a Rem LSS .300 RUM. I will be using Sierra's advised accuracy load of 82.4g of H-1000. I have always done load development at 100 yards, but what are the advantages of 200 or 300 yards? Or should I just stick to 100 yards? Another thing is I think something is a little screwy either with Sierra or some internet site. The Sierra book lists a max of 82.4g of H-1000 for a velocity of 2800fps. On accuratereloading.com they start at 85g and there max is 92.5 for a velocity of 3050fps. That is 10g difference of a max load. I'm sure someone in here knows for sure. Anybody have any good 220g SMK load data particularly with H-1000? I will be shooting a couple loads tomorrow.