It's closer to 25fps per inch with the calibers I shoot. Examples of barrel lengths bullets and velocities. Wife's 260... 20" barrel shoots 140gr class at mid 2600fps. 123gr class lil above 2800fps. Its job is deer and varmints Next my creedmoor.... 140gr class I'm running at 2740fps. Now I'll use this all the way up to elk and black bear out to 300 yards. Finally 30-06....."was a 24"barrel" 150gr bullets mid 2900 185gr bullets mid 2700. With rl26 I ran 178eldx at 2820fps. New barrel will be 26" 11twist and desire to push 200gr to mid 2700 with rl26 we'll see. The other point I'm trying to get across is this.. There is a rifle for every task and a task for every rifle.