As others have stated the BHP was designed for the 9mm but it was later redesigned to accommodate the 40 S&W round. There are even 357 Sig conversions.
Also do not over look the 30 Luger. There are not a ton of them out there but they exist.
I have owned a 40 but did not like the balance vs the 9mm. All my current ones are 9mm.
You’ve got some REALLY nice BHPs WVS...enjoy seeing 'em every time they come up
.
Again…FWIW, I'm fond of all my BHPs...even the .40s
...but the 9mmP IS what the BHP was designed for and there's just something about the forged frame...v. the cast frame, that feels "just right"
.
As for the “others”:
The 7.65P (.30 Luger) is VERY soft shooting...but expensive to feed and of "limited" use outside the neat to have/fun factor
.
A properly fit...think Don Williams, .40/357Sig BarSto Conversion is a joy to behold...as is the .40/9mmP BarSto conversion
.
The defunct...for a reason
, .41AE Conversions...have a reputation as being hard on the forged frame BHPs they were intended for and have...at times, be frustrating...and honestly, have become just odd conversation pieces
. Mine only get used with cast frame BHPs now.
If there's one BHP I "NEED"
, it's one of the 9x21mm BHPs intended primarily for the Italian market. I've never seen one for sale...outside Europe