Greetings!
About 6 years ago, I started a VERY thorough process of finding the optimum handload for my Remington 700 VS in .308 Win. (recently sold). I tried 10 different powders and loaded for velocities at 5 different increments across the velocity spread for each powder. I only used 1 type of bullet for all reloads - Sierra 168 gr. HPBT Matchkings. I loaded 10 cartridges for each test, making the entire test consist of 500(!) individual cartridges. I spent 2 months on this project, in the loading room and at the range - keeping careful records.
At the end of the experiment, I found that IMR4064 powder loaded about 1 step below the top-end of the velocity range for that powder produced the most accurate loads - the three groups I shot with that load produced hole sizes of (1) 0.25", (2) 0.4", and (3) 0.3". The 3rd group (0.3") was the 4-shot group, as 10 rounds does not divide evenly into three 3-shot tests I always shot the last group with 1 extra round.
Take it for what it's worth... your rifle probably is different. However, I think it DOES say something about IMR4064, at least in terms of consistency.
Best wishes,
Bawko
