A while ago I asked here, and other places what was the difference between the Hornady regular dies set and the "cowboy" die set.
Well, after waiting over 1 year to get the cowboy die set, I gave up and got the regular die set. Then 2 weeks later I found the Expander die by itself at Midway. So I bought it.
The standard set has an expanding die like other dies I've seen - nothing unique - all one piece so you can't measure nipple that does the expansion.
The Cowboy expanding dies are TOTALLY different. The part that does the expansion is a floating piece. For the 45 Colt there are 2 different sizes.
The one with the longer nipple for the expanding part is .452 dia and the last ~.100" of length goes to .459".
The shorter one is .4505" dia and last ~.100" of length goes to .457".
So, If you seat the expander part all the way, you can get a bell on the case so you don't rub off any coating on the bullet.
There are directions specific to the cowboy expanding die. They can be found here:
https://www.hornady.com/support/user-manuals#!/Look for "Cowboy Expander Dies Instructions"
Here is a pic of the 45 colt cowboy sizing die
Here is a pic of the 38/357 cowboy sizing die
Here is one of the places I inquired about the cowboy die set.
https://czfirearms.us/index.php?topic=112668.0I called Hornady and the guy said for lead get the "cowboy" due to the typically larger diameter bullet. For jacketed get the standard dies. Both can be used but neck tension might not be good enough for the jacketed with the "cowboy" dies.
Sizing die is the same, the expander and seater are different between the 2 sets.
Currently no clue what is different for the seating die.