im not familiar with the custom ks mounatin either, but I have a rem 700 mountain rifle in .308 win. I absolutely love this rifle and would never get rid of it. its a light compact gun that handles very well in the woods and is very accurate considering it has a toothpick for a barrel. All but 2 deer I have killed in my lifetime were with my mountain rifle, Ive taken one elk and many coyotes with it too. out of all my rifles it would be my go to gun theres nothing it wont handle.