lots of good info on this thread, the only thing that I can add is as a general rule of thumb is when I select a powder, I look into the load data and start by choosing a powder which shows low pressure with decent velocity at max charge. this load is usually a slow burning powder for the caliber. the reason I do this is because slow burning powder has a more gradual pressure curve than fast burning powder. it is much easier on the brass and the rifle, and for some reason, usually has very good accuracy. start at minimum and work up in .2 of a grain, or if you are OCD like me .1 of a grain to find the most accurate load. I pay absolutely no attention to velocity, as finding an accurate load is the goal. load up 5 rounds for each increment and keep these rounds well marked, I usually put masking tape across the base of 5 rounds and print on the tape what the load is. when I am at the range, the tape gets transferred to the target after a string of 5 rounds. the downside of this technique is that the masking tape gets difficult to remove if it stays on for a long time.(don't ask how I found this out) keep a watchful eye on pressure signs.
