Not sure if there is a difference in the available mounting length of the K6 and K4, but tried desperately to get a K6 to work on a s/a MKII Ultralight (.308) and it was a definite no-go. Most of my scope's occular end ends up between the rear of the trigger guard and the trailing edge of the tang, so I don't mount them that far back compared to most people but I just couldn't get it to work. Ended up with a VX III 2.5-8 that JUST did work.
John
