Well, I'm an old cast bullet shooter so the .25 calibers are better for me. I also look at what velocities that the available bullets expand at, and find a better selection in .25 than .24. Game will never know the difference for sure probably. Rims are good for some guns, and a problem in others, pick your gun, and get a caliber to match. I also think that part of the reputation of the killing power of the 6.5's, and early 7mm's was due to the fast twist rates common in those guns. I also have this far fetched idea that if there is any such thing as a true "brush" gun it is one with a fast twist, and medium velocity, though I may be way out of line on that. Watch a football sometime though. If it is thrown with a rapid spiral, and gets "ticked" it often settles back down and reaches it's mark. If one is thrown with a very lazy spiral, if it gets "ticked" it careens off course. So, there is some reason, or preference for some calibers that can't be fully justified with ballistics, or glitzy advertising.