S&W interchangeable compensators

[JohnFM]

Certain S&W revolvers have a compensator for jacketed bullets and another for lead.
Does anybody here know just why they have to be made differently?
I've asked a few guys I know, but no one seems sure about it.

[ratboy]

to sell more parts?

:confused:

[JohnFM]

Damn, thought someone knew something---------------