I have 2 sets of .32-40 dies - RCBS and RCBS Cowboy.
I also have many other dies including Lee, Redding and CH.
The standard RCBS seater will have a smaller guide bore for the bullet. The bullet guide bore in the RCBS Cowboy die is about .002 larger and permits the use of a larger bullet.
The expander is not very good compared to a stepped expander like the Lyman M die.
The Lee dies generally have both a poor seater and a very poor expander.
Your Cowboy dies are probably suitable except you need a better expander such a custom expander or at least an M die from Lyman.
Some people like CH dies but there is nothing really different about them dimensionally other than the FL sizers tend to be tighter like Lyman's.
If you want minimal sizing get a Lee FL die body and have the neck honed out to your specifications.
Quote:Travelor I am currently using Cowboy Dies. Have been for a number of years. I shoot lever guns and the single shots in competition. Thanks for your input. Thanks for the other suggestions. I am going to try CH4D Dies, I have heard good results from them
Goatneck.....