Don't let my jaundiced bore scope snobbery jade your opinion of Merkel. It frustrated me to no end, but my 9.3x74R shoots like a dream, fits me well and is one of my favourite pieces. It cost half of a comparable Heym. When you look at enough bores, you discover that most rifles shoot really well even with a rough bore. All things are relative and few manufacturers actually give a damn about polishing the bore to look like a Lilja or Kreiger match grade bench rest barrel.

Manufacturers that I have seen with consistently good bores:

Sako
Heym
Blaser
Weatherby (all of the MK Vs, but particularly those with the Criterion button rifled barrels - never looked inside a Vanguard aka Howa)

The more garden variety rifles commonly seen in the fields of North America are not so pretty in my experience on the inside of the barrels HOWEVER, many will shoot REALLY well.... Remington model 700s come to mind as good shooters, and the last couple I've had were truly despicable in their quality control. I've had to stop myself from churning rifles based on the bore scope. Now I use it primarily to look for throat erosion, fire cracking, and rust / pitting, particularly before buying a used gun.