The twist in my 7x300 Weatherby is 1 in 9, and the barrel is 30”.
Velocity is 3350 plus with the 162 Hornady match bullet using 7828 powder.
I have 2 of these rifles, one has a 27” barrel on a heavy sporter, velocity is the same in both guns using the same load.
Problem here is that most have never actually shot the guns at those distances to actually see what happens.
But instead just rely on published data.
Fact is that the (original) 162 gr Hornady HPBT match bullet had a BC of .725.
After a few years, (early 70s ), they redesigned the bullet, and that reduced the BC by about 100.
I still have a few boxes of the early high BC bullets with that number printed on the box.
But our test was done with the later version with the lower BC number.
Mind you i could care less what others think and do.
But fact is that anybody thinking that they can turn a 7 Rem Mag into a better gun by using higher BC bullets, is living in a dream world.