a 7mm rem mag and a 243 win is the calibers im wondering about thanks
............From my 16.5" tubed 300 WSM Ruger Frontier compact, I have done extensive chrony testing (using identical reloads), comparing velocities with two other friend`s 24" barreled 300 WSMs. This was done in order to determine just how much of a velocity loss (per inch) there really is as well as determining the overall percentage loss. Can`t comment on your 7mm mag or .243 though.
With my varied reloads and depending on the load, the across the board average loss ranged from 16 fps to 22 fps per every inch of shorter barrel length.
In an online article by Dick Metcalf which I can reference, he chrony`d 7mm/08 factory ammo from a 16.5" tubed Ruger Frontier and the same ammo from a 24" tubed 7mm/08. Taking his velocity figures and doing the math, taking the difference in velocity between the two, then dividing by 7.5" of shorter barrel length, there was a 16.4 fps (per inch) difference.
Only a chrony will know for sure. But there is absolutely no difference in any game stopping power between a 22" vs a 24" barrel with your two cartridges.