Most people, even some experienced shooters, see handguns as a tool that can only be used effectively at 7 yards or so. It is true that a handgun is designed for shorter ranges than a rifle, and because of the length and therefore fewer contact points, will never be as accurate as a rifle, but the fact is they can be effective at much longer ranges than most people think.
What we are really talking about is the maximum effective range of a handgun which is defined as "the maximum distance at which the capability of the handgun, ammo, and shooter are consistent enough to put every shot on target. MER will change with target size, handgun accuracy, and ammo consistency but for most handguns, consistent shots at 100 yards or more are possible.
To better understand what a handgun is capable of we must define the type of handgun we are talking about. We are not referring to any of the specialty 2 foot long, bolt action pistols (short rifles) used in long range hunting and silhouette competition. We are talking about your normal "over the counter" carry semi-automatic pistols that you would buy for carry purposes.
Now that we know the type of pistol we are shooting, we need to understand what variables affect accuracy. The skill of the shooter, consistency of ammo, and capability of the pistol all determine how tight groupings will be at a specified distance.
The foundation of accuracy is the capability of the pistol. The ammo and shooter can do no better than the handgun is capable of.
If we remove the shooter variability we come as close as we possibly can to seeing just what the pistol can do. Many shooters are interested in this as everyone wants to buy the pistol that is the most accurate right out of the box.
There has been quite a bit of pistol testing done already using a Ransom Rest that is a vice-like metal device that keeps the pistol in exactly the same position throughout a number of shots in order to get a measurement in group size to determine the firearm's accuracy potential with a given ammo.
I have searched high and low for data from this rest in order to compare different makes of pistols using similar ammo. I'm sure it is out there somewhere but I have yet been able to find it.
Anyway, I have observed many pistol tests using this piece of equipment and can confidently state that all factory produced semi auto pistols on the market today will shoot from 1.5 inches at 25 yards to 5 inches at 25 yards, depending on ammo, with the average being somewhere around 3.5 - 4 inches.
Most people would be very happy with a 4 inch group at 25 yards, but don't forget we are speaking only of the pistol's capability. The rest has removed all of the human variability. Now we must add the shooter's error. Really good shooters can approach groups that are close to the pistol capability as their error is very small but average shooters will add anywhere from 1 to 3 inches to the equation.
This may seem like we are splitting hairs, and to some extent we are. Honestly, an inch or so doesn't mean much with what most people will do with a pistol during it's lifetime but to answer the question "how far we can accurately shoot a pistol", let's proceed.
So, with a good shooter, average pistol, and average ammo you can expect somewhere close to a 5-6 inch group at 25 yards. This would be considered acceptable accuracy by most anyone, except maybe bulls eye competition shooters.
Now as this distance decreases, of course the group size follows, and vice versa. At 100 yards the capability of the pistol and ammo may be 15 inches or more. So at 100 yards, on a full man size target that is 24 inches at the smallest measurement which is width, the shooter can introduce 9 inches of variability into the shot and still be successful.
If the target is 24 inches wide at 100 yards, and at least that tall, you can land shots fairly consistently if you as the shooter are good enough. So what is the maximum effective range of a pistol?
Your maximum effective range will vary with pistol, sights, ammo, ability, etc. My MER will probably be different than yours with a given pistol and ammo because of these factors.
So all we can say when asked what the maximum effective range of a pistol is: "it is the maximum distance at which the capability of the pistol and ammo plus the shooter's capability are slightly less than the size of the target". Any other answer is just taking a stab in the dark for a given situation.
If you are shooting at a golf ball, MER may only be 2 yards. If you are shooting at a man sized target, MER could be 110 yards with one pistol and only 50 yards with another.
My whole point here is the question can't be answered generally. It depends on too many variables. You can guess at what MER might be but that is all it will be ......a guess unless the actual shooter, ammo, and handgun variability are considered for that specific situation.
How to increase maximum effective range with your pistol
Practice This is common sense. To shoot better at long or short range with a pistol requires practice, and a lot of it. The more you practice, the luckier you will get as stated by Lee Trevino an old world class golfer. The main things to practice are the fundamentals. Mastering these will definitely increase how far away you can hit with a pistol.
Trigger press is especially important. Having your finger pad located in the wrong place on the trigger and / or having a finger action that does not results in the trigger coming straight back is the largest source of inaccuracy with a pistol.
You must be able to dry fire with absolutely no movement in the front sight before you have any hope of increasing your effective range.
Red dot sight Most pistol factory iron sights come with a front sight that covers most, if not more than, a man sized target at 100 yards. Not that you can't hit this target at 100 yards with iron sights but you must focus not only on having the sights on target, but having the target centered with the front sight. Then the rear sight must be aligned. These tasks are tough even for the experts on small targets at long range.
A red dot removes the task of lining up the front and rear sights. The bullet goes where the dot is. It also improves your ability to judge holdover at distance and therefore increases your hits further out.
Even up close your groups sizes shrink with a red dot sight. I was in a defensive pistol class with a guy who had a red dot before I had decided to install one on my pistol. His groups at 10 yards were one tiny ragged hole. After seeing this, I puchased and installed one on my pistol and immediately my accuracy improved.
Some are hesitant about red dot sights because they do have the ability to fail where iron sights don't. I now have had several Vortex red dots on pistols for more than 3 years now and have never had a failure when I needed it. I change the batteries every year whether they need it or not. Below are the red dot sights that I consider to be a good value
I own all of them.
I have written an article that gives you more information on red dot sights for pistols which should be a big help to you in making your buying decision. Check it out here.
A simple statement of how far you can accurately shoot a handgun can't be answered correctly, but or a specific situation, handgun, ammo, and shooter the maximum effective range can be pretty accurately estimated. For most semi automatic pistols, a good shooter can consistently hit a man sized target at 100 yards and slightly beyond. After that, the consistency of the pistol begins to open up to the point that a larger target would be needed for consistent hits.