Allen: Mine were Douglas and Kreiger barrels, and one pre-64 M70, which was the least accurate, but still pretty good!
The custom barreled rifles were very accurate; I always found the round easy to get to shoot well.
One of the most surprising was an out-of-box Ruger that was very well-behaved;this was back when Rugers were known for,well, variable accuracy, but this was one of the good ones.Like the 375, the cartridge is a good shooter. So is the 340 Weatherby.
