Silhouette shooting requires a scope to be relatively easy to adjust due to the time constraints of the match and the adjustments themselves must be repeatable. The glass should also be of good enough quality to not induce eye strain ,as the scope is going to be used for prolonged periods. -40 shot or 80 shot matches and if the shooter is going to use the rifle in both hunter and standard rifle classes.
As much magnification as one can handle and target turrets with good tactile and visual indicators for the adjustments, and must have an objective focus.
Good variable scopes in the 6-24x power range or a fixed power up to possibly 25x.
Target scopes having more hardware in them are typically heavier than standard scopes therefore the weight must not be such to exceed the 8.5 lb
limit of the hunter class for rifle with the scope mounted.
If the combination meets the requirement for hunter it will also be suitable for the standard rifle 10.2lb class.
All the best in your silhouette pursuits.