What is the realistic effective range of a red dot on a pistol?

A pistol red dot doesn't make the gun shoot farther — it makes you faster and more precise at the ranges you'll realistically use. For most shooters that means cleaner hits out to 25 yards, and with practice a dot makes 50-yard hits very doable because you're no longer fighting front-sight focus. The catch is the learning curve: if you don't train your presentation, you'll "fish" for the dot on the draw. Spend a few hundred reps building a consistent index so the dot appears in the window every time, and the range question takes care of itself.