First off, I have never owned a Sako 6.5. That being stated, I will make the following statements: I have worked on and fired several diffrent sako's in various calibers over the years. Everyone of them were top quality and very accrite. By "Worked On", I mean I cleaned them(amazing how many people do not know how to clean a weapon). As for the 6.5 x 55, it is simply a very accrite and proven round. Ten years ago or so, I heard there was a gentleman at the Red Castle Gun Club out in the midwest that was simply amazing with a stock swede M96 out to 300 meters. Never watched him shoot myself but, I heard about it from several that did.
Okay, let's summerize my ramblings. Sakos are one of the best designed and built rifles in the world. The 6.5 x 55 is a time proven highly accrite and great hunting round. Combine the two and you should have a fantastic combination
Just my humble opinion being shared. Of course, I have only had three cups of coffee so far today, things might change. Nahhh, no matter how much coffee I have or have not had, a Sako 6.5 x 55 ought to be a fantastic rifle that will last you a lifetime