Yes, it should be that easy. When I call, they want to know what model gun and serial number I'm calling about. They will then proceed to tell me what type of trigger the gun originally came with, and advise me of whether or not it's in stock. It's seems as though they have difficulty looking things up by part, which was confirmed the last time I ordered a .400" trigger and received a .500" trigger (I guess they felt it was close enough?). I'm hoping someone here knows more than the folks picking up the phone at S&W.

I suppose I could tell them a gun model that shipped with a MIM .400 "combat trigger", but not sure a MIM .400 trigger even exists.