I've got a Merkel in 450/400 3" and while fairly plain, it regulates exceptionally well, and the bores when looked at with a borescope are two of the smoothest I've ever looked at, so much so, they may well be a bit too smooth, as it copper fouls quite badly. I'm currently trying HBN coated projectiles to see if I can alleviate some of the fouling issues.

DC