Which chamber for a custom bolt gun?

[Hooz]

Regarding a bolt action, quite honestly the Grendel chamber is not the place to start if you are chasing the Benchrest bug. It is too much of a compromise and does not get the best from the cartridge if the requirement to run in full auto is removed.

That was the reasoning behind my original question (that still has no real answer, and only one suggestion). Here is what I've found...

Pac-nor offers a "pre-fit" barrel for the 527 chambered in "6.5 GREN MATCH". I used quotes around "pre-fit" because it is a custom barrel, but they have already have the right profile, etc.

CSS has the Lothar Walther "6.5 CSS" barrel, but it is a drop-in for the 527 CARBINE. I'm building a 527 VARMINT (heavier profile) rig.

SAOD Industries offers both the ".264 LBC" and "6.5 SAOD" in a varmint profile, pre-fit 527 barrels (both Lothar Walther).

So far, that makes 4 options (only 3 if I discount the carbine profile barrel), and all four use different chambers. I've found SOME information on the non-Grendel chambers, but a few of them remain a mystery.

So... Back to my original question... Does anyone have any idea which would be better for a precision bolt gun?