Jerry, I loaded some 220 grain SMK's today and went to the range to test them out. I used 90 grains of H50BMG. I use this powder due to the extreemly high pressures my rifle generates. I didnt get a chance to run them though the chrony, but at 300 yards they delivered perfect round holes through the target. It appears that they are stable at least at that range. Its hard for me to get to 600 or 1000 yards until things completley freeze up around here. They were also fairly accurate. Having not used various powder charges 2 three shot groups held sub MOA groups. I would be interested to see if they would get any better with less or more powder. My guess is that they were around 2800 FPS. I am not too suprised that they shot good due to the fact that they are the same length as the 200 ACCUBOND which shoot just fine out of my rig. I have shot the 200 AB out to 650 yards with out any problems. I am sure that the 220 SMK will make 600 to 1K with the 12 twist. Probably not the best twist but should work ok. Hope that helps some.