Rich,
Fair enough to build on a short action, BUT it needs a longer magazine box and for God sakes none of this short magazine box long throat nonsense that Remington did with the .257 Roberts when they chambered that cartridge in the Model 700 Short Action Mountain Rifle.
On my 6.5mm SAUM which is built on a Remington 700 Short Action, I am running a Wyatts box. According to my vernier, the internal length of my Wyatts magazine is 3.099 inches where a standard Remington mag I miked measured at 2.850. I am running the 140gr Berger Huntin VLD and my rifle likes a 0.70 thou jump to the lands. This puts the base of the Berger projectile a fraction above the line of the shoulder - the beginning of the boattail is actually lined up with the bottom of the neck. I'm running 63grs Retumbo with no compression and getting 3075fps from my 24 inch barrel.
Trying to achieve this with a standard Remington mag box would have meant the bullet being seated further into the case that I wanted to avoid totally.