Can an R8 Blaser in .338 win mag be changed over to a .257 Wearherby
With only a barrel swap. If so who has a barrel and scope mount for sale.

Yes, both use the same bolthead (MA). The only other consideration is that the barrels both be the same diameter, 17mm (regular, 19mm (semi-Wt), or target/safari (21-22mm).

Mine is the syntherTic stocked version. Savanna I believe. Told only barrels up to .375 without opening channel. I will mic it before I buy a new barrel. Thank you for the reply. I talked to you at SCI or DSC when I bought this rifle in.338 win mag. It took several animals up to sable, roan, and eland in the Selous. It was awesome and loved the trigger pull. Just looking to get more use out of it.

I wouldn't worry about measuring the barrel. If it's a safari or target barrel, you'd notice the difference immediately. Plus they're much more expensive. I'll look around and see if anyonme had a 257 Wby barrel they want to sell.