Re: 25.06 action
I suppose they wanted to get the larger case capacity while keeping the standard bolt face. The 50 Beowulf is another cartridge that uses a smaller rim (.445") and larger body diameter (.535") and I don't know where they came up with the rim diameter, .005" smaller than 357Mag. There isn't anything special about this rebated rim as they load like any other non-rebated rim cartridge.
I also have a 25/06Rem that I have thought about having rebarreled, a Ruger tang safety M77. It was my late father's deer rifle and the bore is dark and doesn't shoot very well. I have had a couple of 30/06s and several 270Win and don't need a 35Whelen although I think that is a cool cartridge. I have a little model 600 Remingtion in 6mmRem w/18" barrel, and have thought about doing a 6mmRem long range semi-heavy varminter. I may do nothing with it and let one of my kids do something with it as I am getting no younger and my firearm needs are dwindling with age.