I have all three rifles, G11, K11 and K31. I've fired the K11 and K31 but not the G11.

I'm not a competitive shooter, just an occasional shooter for fun but from my perspective, I didn't notice much difference between the K11 and K31 at the range. They were both more accurate than any other rifle (with open sights) I own and they were easy and fun to shoot. My K11 was made in 1917 and the K31 in 1943.

I'm not typically a good open sight shooter, I shoot at 50 yards for the most part and average about a 2-2 1/2 inch group with most of my milsurps. With the Swissicon Rifles, that was down to an inch which was an inch and a half better than the guys on both sides of me with scopes.

I got the K31 first, loved it so much I bought the older ones. Funny thing is, I went to take the G11 to the range and it won't fit in my rifle case. It's 3 inches too long so yes, it is a very long rifle.