I got to handle Blaser rifles at the recent SCI convention in Reno, NV. I was very impressed with the engineering of them and, from the experienced users of them, have gotten the impression that they're very accurate, durable and dependable. I am going to be getting one, hopefully soon, in 300 Weatherby Magnum.
If the source of your Blaser is from the market in Europe, the barrels will be serial numbered. The barrels sold in the U.S.A. have no serial numbers.