I don't know where the idea that Douglas are the typical mass produced barrel comes from. Possibly because they are one of the older custom barrel manufacturers. In reality, they are excellent barrels. Their premium barrels are as good as any. I've used a bunch of them and have never had one which disappointed.
Shilen barrels are also great barrels. I have installed, literally, hundreds of Shilens. Again, none have been a disappointment. My short range BR rifle wears a Shilen. They still win benchrest matches because they still build a benchrest quality barrel.
When I started gunsmithing, the barrels most guys wanted on their custom rifles came from Hart, Shilen, and Douglas. There were aother makes used, of course, but these were the most popular. All of these old line companies still make quality barrels. In fact, due to greater competition, they may be better than ever. Regards, Bill.