As said, depends what discipline you use the pistol for and the effective range of the particular pistol. My Crosman 600 I sight in at 20 metres as I can plink at small targets consistently at that range. My Baikal IZH-46M I use at 25 metres.The Umarex type pistols such as CP88, C225, etc I think 10 metres max.I think it is horses for courses. For instance it is pointless having a quality PCP pistol shooting at short distance of say 6 metres, there is no challenge involved.All this advice applies to plinking. If of course you are shooting a competition at a set distance the sights should be adjusted to that distance.

Baz