Rusty, with regards to rifling, I intend to use an aftermaket 6 or 7 inch barrel with conventional rifeling. The 1 in 9 twist works well in the AR's so it should be fine. I agree that 25's would be better in some respects the reasons mentioned, but I want it in 223, the bullet selection is better and trajectory is flater in 223 and I can think of a few other reasons too! But purley as a wildcat, I think 25 would be a better choice. No patent infringements on a real 10 x 25.......heheehe. My personal opinion is if we are to use sabots, we should be able to get a sabot maker to pony up for a 9mm to 223 sabot. That would sell to a broader market of 9 mm based guns. We could use the dillion 10 X 25 and buy stock barells and dies already on the market!!! Have you considered this taz? I know it would take a barrel change for 10mm but i think start up costs could be pushed on to a sabot maker, like one of the two that I refered to you eariler?