I think I'm with you OP - it'd be nice to know at what barrel length the velocity increase really tapers off. From my research, it isn't a huge taper with most rounds. It's not like it hits max velocity then stays the same and then that's the ultimate barrel length... it slowly tapers off. It seems like most calibers expect 25FPS difference per inch until you hit 24", and then that number of FPS slowly decreases per inch. Because of this, I think for a bolt action in a standard caliber 22-24" is about right. 20" is okay if you're trying to keep it short/maneuverable. I chopped my .308 down to 18" and still ring steel at 1000. Just like all the other responses... it depends. Cartridge, bullet, powder, twist rate, etc etc etc. I would like a 6.5 creed and was leaning toward 24" Sendero profile. If I went with a thicker profile I'd probably go 22 to save weight.