Query RE interchangeability of die bodies

[El Bibliotecario]

My Dillion RL550B uses a Dillon-peculiar die for case mouth expansion and powder charging. Consequently I don't need the die for that purpose which comes with die sets. I am speculating that to reduce cost manufacturers use the same die body for both case mouth expansion dies and seating/crimping dies.

If I am correct, I propose to substitute the seating stem for the case mouth expansion stem and use the expansion die to seat bullets, then use the stemless seating/crimping die for crimping as a separate action. I am assuming the expansion die body may not be internally machined to crimp.

I would welcome comments peculiar to specific brands of dies. TIA

[gwpercle]

I'm looking at the dies on my bench :
9 mm Luger CH
38 Special - RCBS
357 magnum - Lyman
41 Magnum - Bonanza
45 acp - Lyman
The boolit seating / crimping die does not have the same body as the case mouth expansion die.
They are different ...
Gary

[country gent]

There are differences in the geometry of the seater and expander die bodies in length and possibly dia and taper.
I believe a expander body could be converted to seat the plug would need to be a custom made turned to fit. How well i will work with out the bullet dia section at the top I cant say

[El Bibliotecario]

Thats the information I wanted to hear. Thanks.