2 of the fl dies are steel which i use for rifle and i have 2 others that are carbide for pistol. im using a dillon 550b. Thats pretty much how i did it but i keep reading about taking headspace measurements and adjusting to get that right so im a little confused. I did notice when i ran some 223rem in the sizer die the length of the casing seemed to have gotten just a tad larger while my 260rem seemed to shrink, is this normal?
IN A PROGRESSIVE, FL steel dies can be adjusted as described previously (touch the shellplate, plus 1/8- to 1/4 turn so the handle "cams over", then tighten the lock ring). Carbide dies should JUST touch the shellplate, then, run an unsized case into the die, check for the barest sliver of light between the die mouth and the shellplate (there's enough spring in most progressives to ensure this), and tighten the lock ring while the case is still in the die to ensure concentricity.
You don't say what you're running your 223's and 260's through, but common wisdom is to full-length-size any round going into a pump, auto, or lever action. Most quality dies will NOT oversize cases (e.g. push the shoulder back too far), and, unless you're looking for benchrest accuracy out of a bolt gun, this generally isn't a concern.
However, adjusting your sizing dies and checking with a headspace gage (e.g. L.E. Wilson, et al) is generally a good idea. 223's stretching is a common phenomena - shrinkage is unusual...
YMMV...
ok, this info helps alot. The 223rem and 260rem are both run out of ar15,ar10 rifles. ill follow your instructions and go from there. thanks