I just bought a Hammerli 850 AirMagnum rifle (and love it). I have since ordered a compensator so I can shoot it in my yard without disturbing the neighbors. Is it necessary to remove the factory sights to install this accessories?
Probably yes, as most if not all moderators slip over the end of the barrel and secure with set screws. If you're using a TKO you my be able to glue on a front sight from a Benjamin Discovery or a similar model that has a curvature that matches the moderator.