kimber45acp

I apogolise if this has been discussed before, didn't see this on other posts/topics. I am handloading Rainier 230gr RN 45's, and I have noticed if I chamber a round, then eject it, the OAL is .006" -.008" less than it was prior to being chambered. Wondering if I have enough crimp, my crimp is set at .469 using a Dillon 550B. I tried it with Factory Winchester's and the same thing happens... Does this sound right? Anyone else notice this?