I believe 24" is the minimum one should chamber any belted .30 to. I would personally prefer something in the 25" to 26" range. They balance and feel better all the way around.
: Shortening the barrel to 22", will reduce the ballistics to pretty much what a 22" barrel in .30/06 gives with 'Light Mag' and Federals increased velocity factory ammo. The only 'bigger' thing about the .300 in a 22" barrel, is powder charge. You get to burn more powder, wear the barrel faster and absorb more recoil, for little or no gain.
: In this post, I am talking about 50fps to 100fps having no increased effect on game animals - no difference on game or in trajectory that is noticable. If the truth be know, there is probably little difference between a top loaded .30/06 26" and the .300 26" as far as the game is concerned. Just an opinion, of course.