I never had a pro-hunter...but my last encore was a .45 muzzleloader and the hinge pin had a bit of slop, so I put a 1X oversized hinge pin in it and it improve accuracy!!! But not all frames and barrels are the same. I just bought a virgin valley custom guns .50cal. barrel (because i got it really cheep) and i have ordered an oversized hinge pin, a heavier lock-up spring, a heavier hammer sping and steve stratton is doing the trigger job right now!!! Not that any of this is needed!! But I got this stuff just in case!!! My old encore shot ok, but i added the oversized hinge pin and it became excellent!!! I shoot a factory .25-06 barrel and it is incredibly accurate!!!
Good luck and good shooting,
Poe