Difference between MC-130 and HC-130?

So my unit used to operate the MC-130P and have now upgraded to HC-130J. Being a rescue unit having the HC-130 makes sense since the H designation was built for search and rescue and the M designation I believe is for special missions. I asked the crew chief what exactly were the differences physically between the HC-130 and the MC-130 that sets them apart and he was unable to tell me.
Now I do know the MC-130 dud used to have a different kind of nose which was a bit longer and stubby but somewhere along the line it changed to the standard nose we see on all C-130s
Now I do know the MC-130 dud used to have a different kind of nose which was a bit longer and stubby but somewhere along the line it changed to the standard nose we see on all C-130s