Thread: Remington 700 Action Lengths

I'm aware of Remington 700 Actions in short (perhaps up to .308 cartridge) and long, however, is there an extra long action, for the Ultra Mags etc?
I have a .300 Win Mag, that I wish to re-barrel, and I'm thing of getting it chambered for the .300 RUM, on the strength of it! Is the long action on my Remington 700 'long' enough, or do Remington make a longer action for their Ultra mags?
Thanks