How much magnification is mostly personal preference. Iron sights have their place but at 300 yards, a good scope will definitely shrink your groups. For general use a 3-9 is a good choice but at longer distances, more magnification is nice. You can never see to well. Basically, it becomes a matter of choosing higher magnification for better precision at long range or less magnification for faster target aquisition. For target shooting, quick target aquisition is usually a non issue. For hunting, it is an issue. Personally, I wouldn't want less than a 3-9 for the intended use you describe and would prefer more as budget allows. Imo, a 4-16 AO would be great.