I have Coonan, actually two of them. They do not always run right with all .357Mag ammo, if you find ammo that works well they will run right. It's been awhile since I shot mine, but if I recall correctly they favored a "heavier" load, heavier grain bullet and not a reduced powder charge. Never bothered trying Self-Defense ammo. If it were me, I'd go for the 10mm, unless you just want the Coonan to have a almost 1911 that shoots .357; which is exactly why I go mine. Though I don't own that Kimber in 10mm, I have several 1911's in 10mm and they aren't picky about ammo like the Coonan.