Re: 700 Action questions.
In terms of action length, yes any R700LA should work. The problem you may have is with the bolt face. Not all 700LA's have the bolt face diameter you will need for the Ultramag. I believe the Ultra Mags use 0.540" bolt face diameter. I beleive these are other calibers with the same bolt face:
257 Weatherby, 264 Win Mag, 270 weatherby Mag, 7mm Rem Mag, 7mm Weatherby Mag, 7 STW, 7mm Rem Ultra Mag, 300 H & H, 300 Win Mag, 300 Weatherby Mag, 300 RUM, 303 Brit, 8mm Rem Mag, 338 Win Mag, 340 Weatherby Mag, 338 RUM, 375 H & H, 375 Weatherby,
375 RUM, 416 Rem Mag, 458 Win Mag, and the 458 Lott.
If you get one for say a 30-06 your bolt face will require some machine work, to open the diameter.
