I recently posted, asking about the velocity loss going from a 24" barrel, down to a Sako Kodiak with a 21.3" barrel. Well, in the name of research, I went out and bought a Kimber Talkeetna with a 24" barrel in order to do some testing myself.(Who am I fooling? I just wanted a new rifle).
I have began shooting both rifles across the cronograph with various loads. So far, I am getting between 75-100 fps difference between the two rifles. With the advantage, of course going to the Kimber.This is all with 300 gr bullets. Both factory and hand loads.
I am getting around 2520 with handloads from the Kimber and 2425 with the shorter Sako.
I tested some old PMC 300gr x bullet factory loads as well. They are running 2420 in the Kimber and 2350 from the Sako.
I will continue testing with other powders and bullet weights.

Stay tuned.