Well, I have experience with both the Basner and Butler Creek on Mausers. I like the Basner because it is really light. However, I also really like the Butler Creeks because ergonomically, it is a great design. It fits me like a glove with a very slim forend.
I wouldn't worry about the barrel channel on a Butler Creek. Just hog that joker out until it fits. Then you can use expoxy or Bondo get it just right. Then, all you have to do is paint it.
I usually cut off the forends on my Butler Creeks and shorten them up a bit. That tends to make them stiffer.
Right now, CDNN has them for about $35 which is a heck of a good deal.
