Do you think a 26" barrel is necessary for all the long action mag cal.
only if portability is more important then velocity. shorter barrels are more accurate 99.9% of the time.
I read a real interesting article in a gunsmithing magazine years ago. They started with a 24" .308 and knocked an inch off the barrel and recrowned, shooting over a chrony and groups. They did it until the barrel was down to 14", they published the velocity differences which was to be expected. What wasn't expected was the accuracy differences were slim to none. Barrel length has little to do with accuracy. A custom rifle (barrel) should be built to the optimum length for velocity.