I did get the KKM6" barrel for mine, I also bought a LWD 5.5" ported barrel.
I have been working up loads for two bullets. a 200g XTP and a 175 Winchester Silvertip. I am trting to use Longshot powder. So far so good zero pressure signs and so far good velocities, I am looking for a magic number combined with sud 2" 50 yard accuracy. So far I am just above max loadings and accuracy has been very good with every loading.
Before you jump on my loading past listed maximums. The 10mm was effectively "nuttered" after the FBI decided it recoiled too much and was not used by that agency. Look at origional Norma loadings and you will see what the 10mm was designed to do, the fact that it was brought out in the bren ten THEN picked up by Colt in the 1911. The 1911 designed for 20K pressures in a unsupported barrel was the beginning of this down loading.
Companies like Buffalo Bore and Underwood and one other, whos name escapes me. bear this out, as they load the 10mm to its full potential.
here is a couple videos I made at the first firing of hand loads. I had just bought the Go-Pro video and did not have it properly set up for sound. (Apologies)
http://www.youtube.com/watch?v=PN5oAW8-L4IBelow are all shooting factory Win Silvertip ammo form three different barrels with velocities. I was not too happy with what I got... BUT I hand load, so I really don't care what factory stuff does.
http://www.youtube.com/watch?v=HOwMdEbEZi0http://www.youtube.com/watch?v=4qaIqjF0ddMhttp://www.youtube.com/watch?v=XBqjJieV6UwCW