Matching published ballistics obtain in laboratory setting in the field may or may not work. Having used a Chrony for a few years, I have found that standard factory ammunition normally falls short.
I have achieved an average velocity of 2600 fps with the 140-grain Remington C-L at 6700 feet elevation. I have not had the time to fire the 120-grain Remington C-L loads that my brother gave me across the Chrony.
I will take the journey to my Sierra ballistic program and see what it tells me regarding wind drift with a Speer 120-grain bullet drive by a maximum charge or Viht N160. The book shows a velocity of 2895 fps. The cross wind is 10 mph.
200-yard drift of 2.78 inches
400-yard drift of 11.92 inches
One of the things I have picked up over the years using this program is that Speer makes a good bullet.
Using the same program but this time the 140-grain Hornady at 2550 feet per second with a cross wind of 10 mph.
200-yard drift of 2.62 inches
400-yard drift of 11.15 inches
Just for fun I will toss in the 140-grain Remington C-L that I am loading at 2600 fps.
200-yard drift of 2.74 inches
400-yard drift of 11.69 inches
I was given my 6.5x55 by a brother who is has invested heavily into 6.5 caliber rifles, including the .256 Newton (6.5-06), a 6.5x55 Model 70 Winchester, a 6.5X257 Roberts, and 6.5x284 Winchester. Frankly he is the starving gunsmiths dream. He has loaded them with bullets from light to heavy. He has taken deer with 6.5 bullets ranging from 108-grains to 160-grains. He has proven to me that range of bullets is very effective on deer.
When brother was having the 6.5x.284 built I did a bunch of research on loads for it. It seems that the long-range shooters go for the 139+ bullet weight.
http://www.6mmbr.com/sixfive284.htmlI envy those who own modern rifles in the caliber. I build my loads around the Swede 96 action and recommended loads for it. I can attest the old Swede does a good job on Mule deer.