From the same parent cartridge average on high performing 6.5mm bullets are around 10-12% more wind than the 25 variant with 131 ACE. How much of a difference does it take to become noticeable?
5%, 10%, 15%?
10% more wind certainty would matter if a guy was trying to win something amidst real competition.
The last day of a mule deer season a few years back some 25-35 mph winds kicked up as I was examining a heavy buck at 566 yards bedded behind some logs where there was no approach.Besides my wind meter, there was good secondary indication from the sheets of dirt blowing across the meadows between two ridges.
I was shooting 260 AI with 140 bergers at 3111 fps (which is stellar really), and I eventually hit this buck in the last rib with a wind estimate of 28 MPH after watching my kestrel for about 5 minutes. Buck was not releasing from cover.
The kill was OKAY but not the kind I liked. I had to put another in him to dispatch him in the short timespan I prefer so animals do not suffer. If i had not shot 3500-4000 rounds that year with this rifle I would not have taken the shot.
10-12% more wind certainty that day would have been a bonus.