I used to think that , until I bought a bore scope there are a lot of times when the patch will not show it but there will still be copper on a land just before the muzzle( for some reason it's usually a bottom land ) , this may not be an issue for long range but it's an agg killer in short range ,(throws shots ) , if your comfortable with the patch system and It works for you that's great , everyone needs to do what they think is best for their program .at big matches the bore scope is on the cleaning table and we share it,