The Predator Medium action is the solution to the short magnum, 284 Winchester and 6.5x55 Swede case length dilemma. With our BDL setup the magazine box has up to 3.2" OAL allowing the use of the longest VLD bullets by Berger etc. Both McMillan and Manners have inlet programs ready to go.
I came in here to suggest the same thing. I have owned pre-64s and started shooting them about 1964, and owned new ones, and ones in between, including XTRs. The quality of the new M70s is the best ever. And you can find a vanilla long action one in a lower-end stock and finish for little money, as a donor rifle.In terms of non-custom production actions, the most recent FN Winchester Model 70 in standard length action would be pretty much as good as it gets. It is essentially a slightly worked over Mauser 98. The next step up would be a custom M98. I own a recent FN W70 Super Grade re-bored for .338-06 A-Square and I've owned many pre-64 and post-64 Model 70s, and no doubt the most recent ones are the best to date.