Here is a summary of an article I copied from a Reloader Mag, many of you may have already seen it, but it has some pretty good information, he was using Varget.
By Gary Sciuchetti and was published in the Handloader Magazine # 257. Gary's goal was to establish the most accurate load possible for a 308 winchester, and to find out how much each component affects accuracy and which brands may have the greatest accuracy potential. Each change in components was conducted with 4 five shot shot groups, 4 different rests were built all of which allowed the shooter to position the rifle and stand to one side while firing. Thousands of rounds were fired over a two year period. In the summary Gary listed several findings. One was that in his particular rifle, a Sako, that Federal GM Match ammunition was by far the most accurate. He also stated that changing the "quantity" of powder can alter group sizes up to .75 inch. Different primer brands altered group sizes by .313. Changing case brand altered group size by up to .25 inch. Changing brands and styles of bullets changed group sizes up to 2 inches. Seating depth is critical and a change can alter group size by 3 inches. His bullet data chart showed that , of all 165/168 bullets tested that the Match Bergers, and the VLD followed by the Matchking, Interbond A-Max, were the most accurate tested. In the middle of the group were the Partition, Grand Slam, Interlock SP, at the tail end were the J-36, Weldcore, Interlock BTSP, Barnes and Woodleigh.
I hope this is helpful to some it was and is to me.
