Ddgo: I have Rifles in both calibers, a 6mm Remington Ackley Improved and another custom Rifle
in 240 Weatherby!
I enjoy them both very much.
My 240 Weatherby is built on a pre-64 Winchester Model 70 action. It has a Hart 27" heavy, stainless barrel.
It IS capable of EXCELLENT accuracy!
I have used this Rifle for 17 years now for long range Antelope and Mule Deer duty.
I highly recommend the caliber and can see no reason to recommend the 6mm Remington Ackley Improved over the 240 Weatherby.
Over the years I have used three different bullets for my long range (450 to 500 yards) Hunting uses. I have finally settled on the fine Sierra 85 gr. HP/BT!
Yep it kills Deer and Antelope quite well thank you.
AND I don't shoot these creatures at these ranges "just to see blood on the ground"!
What a thoroughly despicable and un-sportsmanlike thing for ANYONE to say!
Best of luck with your friends 240 Weatherby project!
Hold into the wind