24" is usually the standard test barrel length for all non-magnum (rifle) cartridges. 26", however, has become the standard (test barrel) for most of the magnum cartridges. (The ballistics tables don't always mention this, but it is true.) There is a bit of a gain in velocity, more so with magnum cartridges than others, in using a 26" barrel (as someone has mentioned). However, this must be balanced with the handling characteristics of the rifle. In my experience, 26" barrels are most often used for open- plains shooting...or even varmit shooting. This doesn't entail moving the rifle much (or carrying it far)....and usually shooting from some sort of rest or bipod. For any sort of woods or brush hunting, a 24" barrel is more convenient... and a reasonable compromise (for magnum cartidges). A 22" barrel is a good compromise for non-magnum cartridges, unless a short, handy barrel (20", usually), is desired.

These "compromise" barrel lengths are quite fine for any concievable hunting situation, so this is not an issue that I would spend much time worrying over. My Elk rifle always wore a 24" barrel (Browning A-bolt, in 7mm Mag). This was fine. If I had been using a non-magnum cartridge....22" would have been my choice.