When I bought my K32 I thought it had a Sk/Sk barrel but when I measured the bore it turned out it was .010 top and bottom. I guess someone had the bore opened up. Anyway, I wasn't concerned as I was planning on a 32" barrel for sporting. So now someone can grab a 28" barrel that would be good for birds or even sporting. Price is $895 shipped in the lower 48. Money Order of PayPal +3%. Let me know if you have any questions.
Someone asked how you go from fixed Skeet to fixed Improved Cyl. I thought I would post this here in addition to the PM I sent. The barrel was originally .727 diameter and the muzzle measures .722. This results in a .005 choke / muzzle constriction which we call 'Skeet'. A prior owner decided to make the gun 'Improved Cylinder' by having each barrel back bored by .005, enlarging the bore before the muzzle to .732 and therefore achieving .010 of choke. The cost of back boring at Briley is $330 for an over/under ($165 per barrel). Back boring is nothing more than removing a small amount of metal from the inside of the barrel with a hone. Back boring to help with perceived recoil was a trend for a while but eventually manufacturers simply started making 12ga barrels .732. That is the case with Krieghoff. On current K gun barrels they are marked usually 18.6mm (.732) and sometime 18.8mm (.740). There is still plenty of barrel wall thickness if a person wanted to open up the barrel(s) further to give more muzzle constriction or even have Briley thin wall chokes installed ($550). Hopefully that explains how increased choke constriction is achieved. I'm not an expert. I will talk excessively and loudly if permitted. If I got any part of this explanation wrong, please correct my statements.