I'll second Felixs velocity ranges for accuracy. If you take a 30-06 for example and use unique for example. If you go from the starting load to the maximum load you will go thru a few distinct grouping types. Below the sweet spots, you will find vertical stringing lessening as you get up to the sweet spot, then you get round tighter groups at that sweet spot. Add a little more and the group goes horizontal, a little more and it spreads out, then the cycle repeats up to the next sweet spot. I have noticed that the sweet spots are about 1200 and 1500 with that powder. The Lyman handbook describes what happens here. The barrel vibrates, the sweet spots are where the node occurs at the muzzle. See the Lyman manual on this as a picture is worth a thousand words in this case.

Felix-

Thanks for that insight. Your posts are much appreciated. I've been collecting these kinds of "threads" and compiling them into an "e-book" of sorts for myself. The content is reminescent of the book "Cast Bullets" from many years ago by Col. Harrison only with updated info. The breadth of material is something that could only come from many experienced contributors such as we find participating on these forums.

Thanks again for your contributions!

Sky C.