Well written and excellent information in both. There are a few caveats readers need be aware of.
First, few folks will notice the leade angle in the Rem. 40XL rifle's chamber is not the original SAAMI spec one of about 2.5 degrees. It's 1.5 degrees; about the same as the .308 Winchester and nowadays the .30-06 SAAMI spec's the same angle. Back in the 1960's when the .308 was first used in competition, its' 1.5 degree lead angle was a major reason it shot much more accurate than the .30-06 match rifles with a 2.5 degree leade angle.
Second, the RT10 article mentions a 4000 to 5000 barrel life with the .30-06 cartridge. That's a lot longer than what top high power competitors got up through the mid 1960's. Barrel life was typically about 2500 rounds and the best shots would notice a slight loss of accuracy at about 1500 rounds. The .308 Winchester barrels made with the same way went for about 2000 rounds before a very slight loss of accuracy was observed but went for a total of about 3000 rounds before needing replaced. Of course, those who didn't shoot either cartridge as accurate as the top master class folks did would get more apparent barrel life before noticing any loss of accuracy.