When I started shooting my hw97 the first 100ish shots sounded pretty twangy and rough but I never really saw a reduction in accuracy. It seems like it has been shooting lights out from the beginning. By now I have around 500 shots through it and it sounds much less twangy and feels smoother but I haven't noticed my groups changing. Maybe it needs more shots or if these high quality rifles like wiehrauch and AirArms are so good to begin with it doesn't take much to break in. It will be interesting to hear other people's responses.