+1 on g.williker's comment. Standard scopes aren't designed to handle the recoil characteristics of a spring piston airgun. Not that the recoil is dramatic, but its major component is in the opposite direction of that of a firearm. SP's actually experience two forms of recoil, one forwards and one rearwards. Part of tuning an SP involves synchronizing these forces. But they'll still damage standard scopes.
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