I have both, they swap quite easily. I haven't fired either of them that way. I imagine the ejector differences are minimal. I have a Keltec pistol that shoots 9mm and 40 cal with a top end swap. It's no where near as accurate as my Steyrs, but it works.Shooter said:I just realized that maybe I could switch the frames and slides on my Steyr 9 and 40. Has anyone done this successfully??