25 yards is my practical handgun maximum. My vision really doesn't allow me to shoot beyond that with open sights and, in fact, it's often a crapshoot at 25 yards. I'll sometimes put together a 2 1/2" group at that distance, feel great about my marksmanship, and then, follow up my great group with something that would neatly fit within the circumference of a manhole cover.
I'm amazed at the effect that distance has on my marksmanship. At 10 yards I can often put everything within a 1 1/2" circle. At 15 yards, maybe within a 4" circle. At 25 -- see above.
I've only fired one time at a distance of more than 25 yards. Just for the heck of it, last year, I set up a silhouette target at 50 yards, then blasted away at it with a revolver (Smith & Wesson Model 27 loaded with .357 rounds) and with a 1911. I was able to keep every round within the torso outline on the target but that's about it.