Weatherby PA 08 barrels
Not familiar with a PA. A twenty eight inch barrel?
Weatherby sells barrels about 540.00 installed but they oly stocked in 24 and 26 inch, or that was the limit, of my inquiry, on a .270.
Many barrel makers can thread the barrels for Weatherby. A Gun Smith, might have to turn barrel down from some makers, to contour you want.
Some make up to 34 inch barrels.
It would have to be have head space checked and rear of barrel checked for perfectly square and if you just get a barrel blank the Gun Smith will have to chamber it. He may want to ream it anyway even if chambered.
Different profile or sale profile by different makers may require re inletting the stock o a different stock if you go to a heavy barrel, or glassing etc of the barrel channel if the barrel is smaller in diameter or different smaller profile.