I don't think 26" barrels have been standard on most magnums for awhile, unless you are referring to the Weatherby Magnums which do come with standard 26" barrels. Most of the short magnums come with 24" barrels, most of the "conventional" magnums (i.e. 7mm Rem, 300 Win, .338 Win) also are primarily available with 24" tubes. most standard calibers these days ship with 22" barrels in sporters. There are exceptions, of course. The main advantage to the longer barrel is velocity, period. No one ever said short barrels are inaccurate. Theoretically, a shorter barrel should be stiffer, and might even have more consistent harmonics, thereby aiding accuracy. But the longer barrel will always give higher velocity, all other things being equal. The nice thing about the short mags with the 24" barrel is that they handle almost as easily as a 22" barrel long action sporter, yet provide superior performance to the comparable standard caliber. I like mine, a Winchester Model 70 Super Shadow in .270WSM with, you guessed it, a 24" barrel.