May 15, 2017
The last thing you need to be thinking about in a deadly encounter is how far you need to hold low, high or to one side to hit center mass.
Most of today's fighting-type handguns fit with fixed sights have been engineered to put bullets pretty close, but few are actually right on the money. Considering the vast variety of projectile types and weights available, they can't be.
Many experts advise trying several different types of ammo through your fixed-sight carry gun until you find one that hits close to point of aim and then carrying it.
It's not a bad method—if you don't mind spending considerable money to test various types of premium defensive ammo and don't care much about what type of bullet shoots to point of aim. But what if you want to shoot a particular bullet type and weight? Frequently, you're stuck either holding off a bit or you must change your sights to compensate.
Obviously, with adjustable sights you simply adjust them. But what about fixed sights?
Adjusting fixed sights can range from not too difficult to big ordeal. If possible, drifting one sight left or right is the best way to compensate for horizontal point of impact discrepancies. Of course you need to drift the sight in the right direction before you start hammering away with a brass punch or applying pressure with a sight pusher.
Lots of people have trouble remembering which way to go, so here's the rule: Adjust the rear sight in the same direction you want to move point of impact, and the front sight the opposite direction you want to move point of impact.
So if your rounds are hitting to the right, you'd drift the rear to the left (because you want to move the point of impact to the left) or the front to the right (ditto).
For a gun that shoots high or low, the rule is the same: To bring point of impact up, the rear sight needs to be higher or the front sight needs to be lower, and vice versa. And on fixed-sight guns this presents a bit more of a challenge.
If the front sight can be replaced, you need to determine how much taller or shorter the new sight needs to be. The first step is deciding what ammo you're going to regulate the sights for and then shoot several groups with the chosen ammo to figure out how high or low it's shooting.
I prefer shooting at 25 yards because the greater distance is more likely to reveal deviations from your line of sight—and for most cartridges a 25-yard zero enables you to shoot at longer distances if you need to. Use the center of the group to determine how far it's off.
You'll also need to measure your handgun's sight radius, pulling from the rear plane of the rear sight and front sight.
If you measure using a tape marked in fractions, convert to decimals.
There's a formula that calculates the amount of sight change necessary to bring point of impact to point of aim at a given distance.
Take the sight radius in inches and multiply it by point of impact deviation from point of aim in inches. Divide the result by target distance in inches.
Here's an example. The sight radius on my Glock G17 is 6.6 inches, and let's assume my point of impact with a certain load is six inches high at 25 yards. First multiply 6.6 (sight radius) times six (inches high at 25), which gives you 39.6. Then divide 39.6 by the target distance in inches; 25 yards is 900 inches. So you have 39.6 divided by 900, which is 0.044 inch.
If my pistol's front sight is 0.215 inch tall, adding 0.044 to that number tells me I'll need a replacement that is 0.259 tall or 0.26, rounded to the nearest practical number. Then it's a matter of finding a sight that high or close to it.
Conversely, if the gun in the example above is shooting six inches low, subtract 0.044 from the current sight height of .215. This produces a replacement sight height of 0.171 or 0.17 in practical terms.
You won't always find a replacement sight of the exact height you're looking for, and if you're serious about having your elevation perfect, you will have to make further modifications, which I'll cover a little later.
First, let's take a look at several common fixed-sight types and how to approach changing them to bring your point of aim and point of impact together.
Many handguns have one or both sights installed in a dovetail cut into the top of the slide or barrel, and windage can be tweaked to perfection by simply drifting one sight a bit right or left to bring point of aim and point of impact together.
And as discussed earlier, different-height dovetailed front sights are often available from the manufacturer, which can make it easy to fix a gun that's hitting high or low.
On most guns, a dovetailed sight can be drifted to one side or the other to correct for windage.
Simply tap the side of the dovetailed sight base with a brass punch and hammer. If there's a set screw, loosen it before attempting to drift the sight, and be sure to support the frame, slide or barrel that the sight is dovetailed into on a firm surface such as a workbench top.
With some modern semiautos, sights are fit so tightly you'll batter your punch and the sight itself pretty badly before you get it to move. For those, it's best to use a proper sight mover tool to move the sight in the slide.
Unless you want to purchase such a tool from Brownells or another supplier, you can get your sight moved at most gun shops, usually for free. Of course, unless the shop has an attached range, you've got to take your best guess as to how far to move it, go to a range and test it, and come back to make any fine-tune adjustments.
Replacing a dovetailed sight with a taller or shorter version is also best done with a sight push tool. Just drift it all the way out, start the new sight into the dovetail, and use the tool to center it up in the slide.
Factory Glock sights are made of high-impact polymer and can't be drifted for windage with a punch. Hammering on the polymer peens it, simply increasing its snugness in the dovetail without moving the sight. As a result, using an appropriate sight push tool is mandatory.
Glock front sights mount via an oval post that extends down through a hole in the top of the slide. While they can't be moved side to side to adjust horizontal point of impact, they're relatively easy to change out for taller or shorter versions to fix a gun that hits high or low. They're held in place via a small hex-head screw inside the slide.
To replace, use a dedicated Glock hex nut tool, such as that offered by Brownells, and remove the screw. Be cautious: The screw is secured with a medium-strength thread-locking compound. After breaking loose the compound, spin out the screw, pull out the sight blade, insert the new one, and replace the hex screw with a drop of fresh medium-strength Loctite. Tighten it snug, but don't bear down because you could strip the threads. Let the Loctite cure for at least 24 hours before shooting.
Ramp-Mounted, Pinned Fronts
Ramp-mounted front sights typically come paired with a good adjustable sight on a revolver, negating the need to ever change them. However, occasionally there's not enough adjustment in the rear sight to get on target with a particular load. Depending on the ramp and the way it interfaces with the sight blade, replacing it may be simple or rather complicated.
On occasion you'll find a blade dovetailed into the ramp. With replacement in hand, just drift the original blade out and the new blade in. Most blades, however, are pinned to the front ramp. The delicate pin must be driven out, and often the replacement blade must be inserted, clamped in place and drilled before the pin can be replaced.
This calls for a steady hand with a drill press and, of course, the use of a correct-size drill bit and other tools, but this process has the advantage of creating a perfect fit unlikely to come loose.
On the other hand, some replacement inserts come pre-drilled and are rather easier to install, and still other ramps use an Allen-type setscrew or a spring-loaded detent to secure interchangeable blades, making adjustments easy.
Staked Front Sights
Early 1911 pistols and a few currently manufactured 1911 pistols—as well as a few other models, many of them obsolete—have front sights that mount via a post that runs down through the slide and is staked in some manner, usually from the inside.
I'll be candid; I don't often mess with these. If you're brave, you can knock out an existing sight, replace it with a new one of different height, and stake it back in place. Brownells sells appropriate staking tools.
It's not a big gamble if you're dealing with a recently made pistol, but if you have a vintage Colt or other valuable or precious 1911, I recommend sending the gun to a 'smith who specializes in 1911s.
Proceed with caution. Typically, the only reason to file on a handgun's sight is because no replacement versions are available or the replacements won't get you exactly where you need to go. But if you decide to do this, realize you're increasing the risk that you'll screw up your gun beyond an easy fix.
A file often comes into play when a handgun hits low, and a few strokes on the front sight will bring point of impact up to point of aim.
If a handgun hits high, the problem might be possible to correct by filing down the rear sight, but before you attempt it, make sure that lowering the top plane of the rear sight and deepening the notch isn't going to bring your line of sight so low it gets obstructed by the hammer spur, frame or some feature on your handgun.
Unless you have an uncommonly steady hand, you'll want to mask the barrel with electrical tape to protect it from any slips with the file. I like to run a calculation using the formula I described previously and lightly mark the side of the front sight or the rear face of a rear sight at the depth I predict filing to.
Never cut straight to that mark. Instead, take long, slow, even strokes, checking frequently to be sure you're cutting the top of the sight level and making any corrections necessary as you proceed.
It's best to file at the range so you can pause and test your progress on a downrange target. As mentioned, if you go too deep, you're screwed, so proceed slowly. As you approach your calculated final height, shoot and shoot again.
More than once I've flung a few quick shots downrange, found they still seemingly impacted low and continued merrily filing away—only to discover I'd gone too far. Firing a confirmation group is cheap insurance against an irreversible mistake.
Silver Solder and Splices
In drastic cases, replacing a soldered-in sight blade or silver-soldering a piece of steel to the top of a front or rear sight blade can enable a shooter to fix a drastic too-high or too-low point of impact problem.
While it takes a fine touch, adding height to a rear sight is less risky than doing so to a front sight, because in most cases the rear sight can be removed from the handgun's frame or slide.
Brownells offers replacement front sight blades for single-action revolvers, and with care an existing too-low sight can be melted free and a new blade silver-soldered in. For some other fixed-blade models it's harder to find a replacement, so material must be added.
Adding height to a front blade sight is risky on multiple levels. You'll almost surely discolor the bluing on the barrel, and likely you'll have to clean up excess solder and touch-up blue. But depending on the handgun and the situation, that may be an acceptable solution.
If you attempt to silver solder additional material atop a fixed front blade, exercise good technique and be sure you're working with a level, clean and uncontaminated surface. I prefer hollow-wire solder with internal flux.
If the blade becomes loose in the barrel, make sure it stays vertical in its slot and hope that as it cools the solder around it simply hardens and resecures it. If not, you'll have to remove it, clean the base of the blade and the cut in the barrel, and carefully resolder it back in place.
During this process you will, of course, melt the added material that you've just added to the blade loose from its top, and you'll have a balancing act to get it to cool and harden together, straight and in place.
I've got to end with a warning: This last procedure—and also filing, if you're not already a pro at it—is best left to a competent gunsmith. And, obviously, never do either to a vintage or especially valuable firearm.
It's one thing to try your hand at working on a theoretically replaceable gun; it's quite another to tackle changing the sights on an expensive or irreplaceable handgun.