As far as the sudden found speed of the 6.5 CM..... it is over pressure-- WAY overpressure. Quality brass came out that was able to handle/hide the results of that pressure- some powder developments as well
Exactly! +1


My intention was understanding the thinking which makes 280AI great & 260AI not. They are both in that area of only like 4.5-6% performance increase over their standard counterpart. (280 being slightly better) I can understand that simply having some factory loadings in 280AI is pretty huge.
I think over the decades that AI became synonymous with "always better" rather than look and see.