Vernon, Focal, he probably tried to steer you away from the 125 in .177 because almost any pellet you use in that gun will be supersonic. If you like the Model 125, go with a .22 or .25 caliber.
Oh Jeff, I went to look at the info on the Hatsan 125TH [.177] Refurbished rifle and it doesn't indicate what the piston is driven by.Is it a 'Spring' a Nitro piston or Vortex?Cheers to all of you. Vernon.