I do not know anything about this new 6.5, however do know or surmise that a lot of the wearing out of barrels in the past was due to improper cleaning - not wear. Most with a buildup of carbon ahead of and in the throat and the more powder you burn, the greater is the deposit of carbon. If not cleaned out often, the bullets constantly running over the carbon fouling turn it into a ceramic-hard deposit that cannot be removed and yo can hardly touch it with a carbide scribe.
This tightening of the bore near the breech did indeed give the appearance of a shot-our barrel. It was smooth looking and would extent well up the bore. As the carbon become one with the bore and got thicker/tighter, the bullets wold be squeezed down smaller than the rest of the groove diameter and groups would continually increase at an alarming rate, sometimes after as few as 500 rounds. I think that's where the 'worn out before you find a load' saying came from. This is, in my opinion, of course.

Too, many of the old Swifts were simply fouled out, not worn out. People did not know about proper cleaning. Unlike them, we know a patch with 30 WGT motor oil is NOT cleaning. I know of guys on another forum who have resurrected old "Worn-Out Swifts" - purchased at a 'steal' and after days of soaking with solvents and scrubbing - turned them into sub 1/2" shooters again.

With today's better solvents and greater knowledge on cleaning, along with the use of bore scopes to check progress, much of the 'bore wear' of old has been reduced - again, in my most humble opinion.