Con,
The 2 BLR's in question both have Pac-Nor barrels, so don't expect them to be undersize.
My P14 has a TSE C/M barrel, and I know it's tight, that's why I can't seem to get much grunt out of it, although after getting my copy of the Hornady 8th edition manual, my loads chronograph similar to the manual.
My 416 Taylor has a stainless TSE barrel, which is lapped by Tony, he does not lap C/M barrels unless you request it, and pay for it!
Oddly, I can get better velocities out of the Taylor, without pressure problems.
I'm starting to think the Taylor is about the most efficient of the 416's, grains of powder to velocity produced.

Not sold on the 416 Ruger by any stretch at this point in time.

David