I would crony the gun to be sure power is up to snuff. They have a problem with leakage due to welding on the scope rail. The first one I tested shot at about 14ftlbs which is low for a standard gun, but horrible for a magnum. That leakage also contributes to accuracy problems and scope breakage.
If you don't have a crony you can open the gun up and look to see if the problem exists which will be obvious with holes in the welded area that the main seal passes over. If you have it apart you might as well install a new main seal since the originals are almost always damaged during install from the sharp edges of the cocking slot. So ideally you should file/grind/sand those sharp edges before installing the new seal. Plus a good aftermarket seal will be better all around anyway. There are other things you can do while it's apart to make the gun better, like smoothing the rough transfer port, making sure the breech seal has a smooth surface to seal against, piston buttons to reduce wear and cocking effort, etc... I have info on that stuff if you're interested in going that far.