After you buy optical scope the next question will arise – what is most reliable way to mount it to avoid zeroing after few dozens of shots? Usually almost all modern scopes are provided with aluminum rings – and this is not exactly what we need. For better result you have to use steel rings.
Despite of slightly bigger weight of steel rings they are keeping your scope from zeroing after few shooting sessions. Steel rings have quick-disconnect mount for Weaver-Picatinny rail. Internal diameter is usually 30 mm. They are provided with special key used for mounting (Allen key). For best result Loctite shall be applied on threads. Rings on the rail are tight by hand; removal is also easy and convenient.