If it were my rifle I think I'd do as Daryl suggests. That is to say, ensure you have positive even bedding of the action and reinforce, a clear barrel channel, and even, positive contact, at the muzzle. Take it to the range and test that arrangement. If the results are poor or inconsistent experiment with paper shims of varying thicknesses placed between the muzzle and cap. If this degrades accuracy it may be time to consider reducing the amount of upward pressure on the muzzle. Just use an appropriately sized dowel and a bit of sandpaper to slowly relieve the upward pressure. If this results in an improvement, keep doing it until you free float or accuracy begins to decline. If it declines, shim the muzzle cap at the appropriate pressure point to restore accuracy and seal.