Sorry guys, I'm just anxious to get an answer.  I would like to get back on it tomorrow.
www.ar15.com/forums/topic.html?id=132515

I used one briefly on .223 a few months ago.

I set it up to just put a noticeable double ring around the case mouth at the bullet junction.  You can visually tell that it crimped without deforming the brass much.

I don't use it anymore.  It just seemed redundant.

I use it on 45 ACP. When I set it up I put in a factory round and screwed the die down on it. Snuged it up and then reloaded some. They were perfect. I like the die because it sizes the 200 grain cast rounds at the end. I get good accuracy and the brass is holding up. As for AR 15's, got me!

I use the .223 factory crimp die on my Dillon XL650.  I set it in the last station.  I always set everything up with a test cartridge (no powder or primer).  I run the cartridge through all the stages, adjusting each until it is right.  I always start with too little (too little seating, too little crimping) and then I adjust each down individually until it's perfect.

With the crimp die, I position the case (with seated bullet) at the top of the stroke and screw the crimp die down until it touches and gives some resistance.  Then I back the press down a bit and adjust the die a little bit, then run the press to the top, again.  I keep doing this until I get the crimp I like.  I usually go for a medium crimp, where the crimp lines in the case are visible, but not enough that it really caused a deep impression.