I have been using a short length Malcolm 6x straight tube scope on my Krag lately.
The glass is precisely made, multi-coated etc.
Very clear.
They also do an 8x with the larger objective lens for more power, parallax adjustment, and changeable reticles if you like.
Mounts are very precise and repeatable.
Here it is, shooting at 650 yards the other day.
This setup is only $450 with the mounts.
Their 8x goes for $575 with different (even nicer) mounts.
This image is from a
Gun Digest article 
I haven't used one of their 8x scopes yet, but I am looking at giving it a try.
