Forming brass for the 17-223 is a little more (but not much) involved that the 6 x 45. Most guys F/L resize using the .223 die w/o guts, then run thru the .17-223 die with guts. Me, I'm anal, so I run it through a F/L .223 die w/o guts, through a .19-.223 die (got it from James Calhoon) w/o guts, and then through the .17-.223 die with guts. I prefer to step my brass down from .22 to .19 to .17, instead of .22 to .17. The 6 x 45 is a simple run .223 brass through the 6 x 45 die and load.