Comparing two different barrels really means nothing bud. Different quality, twist, rifling, and on and on.
Even my last two 6mm barrels, made by Krieger, same twist, same length, same reamer (which has only cut my two chambers), same load, same Chrony same everything are 70 fps apart.
Apples to oranges. I'll never own a barrel over 22" the rest of my life.
I've even had everything cut down expect a fluted factory rifle.
I like them handy...
I wanted 22" at first on my 6.5, but after handling a couple of 20" rifles and seeing some Long Range targets I was more than satisfied at 20".