Casey, I had always figured that to be the case, although I had never seen anybody put it into print before.
Look at it this way: The limiting factor in a load, what ever the powder, is peak chamber pressure. And according to all known gas laws, pressure is directly equivalent to pressure.
With a slow powder like H4831, the barrel is exposed to that high temperature for many more milliseconds than it is with an extremely fast powder.
Bullet speed is more dependent upon duration of the pressure peak than it is of the peak height.
As to the OP. I have read of US Army test with the '06 where the accuracy of the barrel actually improved over the first 3000 rounds fired. Accuracy maintained to the 7000 round mark and then started to deteriorate. At 10,000 rounds the average army rifle in 30-06 shot as well as the day it left the factory.
BUT, the military '06 was a different beast than the modern 270 driving a 130 gr bullet to maximum velocity.
I have managed to wear out one rifle barrel. It is a 264 Win mag, and I spent a lot of time, bullets, and many pounds of powder trying to achieve the elusive 3200 fps with a 140 gr bullet.
It took me 2500 hundred rounds to burn up the throat on that rifle. If the copper is scrubbed out, it will still put the first three into an inch on my 132 yd target. But the next five will open up to about three or four inches. And it takes a long while with Sweet's 7.62 to get it clean again.
I would guess, as long as you keep her cool, you should get 3500 rounds or better from your 270.
