The effective range of a gun scope depends on several factors, including the magnification level, the objective lens size, the quality of the scope, and the shooter's skill level. Generally speaking, the effective range of a gun scope can vary from a few hundred yards to over a thousand yards, depending on the type of firearm and ammunition being used.

For example, a hunting rifle with a variable magnification scope and a large objective lens size may have an effective range of 500-800 yards. A sniper rifle with a high-quality scope and specialized ammunition may have an effective range of over 1,000 yards.

It's important to note that effective range is not the same as maximum range. Maximum range refers to the distance that a bullet can travel before losing velocity and accuracy. Effective range refers to the distance at which a shooter can consistently hit a target with a specific firearm and scope.

The effective range of a gun scope can be improved by selecting the right equipment, practicing good shooting techniques, and developing skills through training and experience.