How to Adjust a Williams Peep Sight

Which Way Should You Move the Peep Hole?

When you are standing at a shooting bench with a small screwdriver in your hand, it is easy to second-guess which way to turn the sight. The golden rule of adjusting a rear peep sight is simple: move the rear peep hole in the exact direction you want the bullet hole to move on the target.

If your shots land low, raise the rear aperture (the peep hole you look through). If your shots land to the left of the bullseye, move the aperture to the right. If your shots hit high and right, lower the aperture and shift it left. You always move the rear sight in the direction of the correction you want to make on the paper.

This works because of basic geometry. When you look through the peep sight, your eye looks through the center of that hole toward the front sight and on to the bullseye. If you raise that rear hole, you must tilt the rifle barrel upward to bring the front sight back into the center of the opening. Tilting the barrel upward raises the point of impact on the target.

Shooters often get confused because front sights work in the opposite direction. If you were adjusting or filing down a front sight post on the barrel, you would move it away from your miss. But for your Williams rear peep sight, never overthink it. Always move the aperture toward the spot where you want the bullet to hit.

Which Williams Sight Style Do You Have?

Before touching any screws, check which style of Williams sight sits on your firearm. Williams makes two primary mechanical designs, and each handles adjustments differently.

The first style is the micrometer click model, commonly found on the Foolproof (often stamped FP) series. These models feature dedicated adjustment screws or target knobs. Turning the elevation screw on top moves the aperture up or down in tiny clicks. Turning the windage screw on the side shifts it left or right. These sights feature small etched white or silver index marks so you can track how many clicks you move.

The second style is the slide-and-lock model, found on the Williams 5D series and the Williams Guide Receiver Sight (WGRS) models. These are compact, rugged sights designed for hunting rifles without click dials. They use a sliding bar held in place by friction and a locking set screw. To adjust a 5D or WGRS sight, you loosen the locking screw, manually slide the bar along a scale, and tighten the screw back down.

Both styles share one critical detail: the main body is machined from lightweight aluminum alloy. Aluminum is light and rustproof, but its threads are softer than steel screws. If you turn an adjustment screw on an FP sight while its lock screw is still tightened, or if you force a sliding block on a WGRS without loosening its binder screw, you will strip the aluminum threads. Once those threads strip, the sight will no longer hold zero, and the body must be replaced. Always loosen the lock before making an adjustment.

How Do You Zero the Sight Step by Step?

Zeroing your rifle means setting the sights so your bullets hit exactly where you aim at a specific distance. Taking a slow, methodical approach at the bench keeps you from wasting ammunition or chasing stray bullet holes.

1. Clear the firearm and build a steady rest. Point the muzzle in a safe direction, drop the magazine, open the action, and inspect the chamber visually and with your finger to confirm no round is loaded. Set up the rifle on a solid rest using sandbags or a shooting bench block. Never sight in while shooting offhand, because normal body movement will mask your adjustments.
2. Start your target at 25 yards. Starting at 100 yards is a common mistake that leads to missing the target paper completely. At 25 yards, even a poorly aligned sight will usually put a bullet on the paper, giving you a clear starting point.
3. Shoot a three-shot confirmation group. Aim at the center of the bullseye for every shot. Look through the rear peep hole, focus your eye on the top of the front sight post, and place that post on the bullseye. Your eye naturally centers the front sight inside the circular opening of the peep hole, so you do not need to center it manually. Fire three steady shots without moving the rifle rest between shots.
4. Loosen the positive locking screw. Unload the rifle and inspect the sight. Locate the lock screw. On an FP model, this is a small set screw on the side of the elevation or windage track. On a WGRS or 5D model, it is a slotted binder screw clamping the slide. Use a proper hollow-ground screwdriver that fits the slot snugly. Back the lock screw out a half-turn to one full turn. You only need to relieve clamping pressure, not remove the screw.
5. Adjust elevation first. Settle your up-and-down adjustment before touching side-to-side alignment. If your three-shot group landed two inches low at 25 yards, raise the aperture. On an FP click model, turn the top elevation screw in the direction marked UP. On a WGRS or 5D model, nudge the sliding bar upward along the stamped hash marks. Keep movements small at 25 yards, as a tiny shift moves the bullet impact significantly.
6. Adjust windage next. If your group landed to the left of the bullseye, move the aperture to the right. On click-adjustable models, turn the side windage screw toward the R mark. On sliding models, slide the windage bar slightly to the right.
7. Snug the locking screws. Tighten the locking screw with light wrist pressure until it is firmly snug. Do not overtighten. Hand-snug pressure holds the sight securely against recoil without damaging the aluminum housing.
8. Confirm and stretch the distance. Fire another three-shot group at 25 yards to confirm your shots hit center. Once your group lands on the bullseye, move your target out to your final distance, such as 50 or 100 yards, and repeat the process with very fine adjustments.

Why Did Your Sight Run Out of Upward Adjustment?

A common problem at the range happens when a rifle shoots several inches low, but the rear peep sight has reached the top of its track. When the elevation bar cannot go any higher and your bullets still hit low, you have run out of upward travel.

This does not mean your Williams sight is broken. In nearly every case, running out of vertical travel means the front sight post on the barrel is too tall for the rear peep sight.

Receiver peep sights sit naturally higher off the bore of the rifle than standard factory rear notch sights. Because the rear sight sits taller, your eye sits higher. If your front sight blade on the barrel is too tall, lining up the sights forces the barrel downward, causing your bullets to strike low on the target.

To fix a rifle that shoots low when the rear sight is maxed out, you need to lower the front sight. Replacing the front sight blade with a shorter bead or filing down a plain metal post allows the barrel to tilt upward, raising your bullet impact on the paper.

The opposite can also happen. If your rifle shoots far too high with the rear sight lowered all the way down, your front sight is too short. In that scenario, installing a taller front sight will force the muzzle down. When balancing iron sights on rifles or setting up backup units like the best iron sights for cowitness with red dot sights, matching front and rear heights is what gives you enough travel to zero properly.

FAQs

Do I need a special screwdriver to adjust a Williams peep sight?

Yes, you should use a hollow-ground gunsmith screwdriver rather than a standard household wedge screwdriver. Williams sights use small screws that can deform easily if a tool slips. A hollow-ground bit fills the entire screw slot evenly, giving you clean turning force without burring the screw head or slipping onto the aluminum sight body.

Should I remove the threaded aperture disc when hunting?

Many hunters remove the small target aperture disc and shoot through the larger threaded opening as a ghost ring. A small target aperture gives you sharp focus on paper targets in bright daylight, but it restricts light at dawn and dusk. Shooting through the open outer ring lets your eye gather maximum ambient light in heavy timber while still centering the front sight naturally.

How tight should I tighten the locking screws on a Williams sight?

Tighten the locking screws until they are firmly snug using light wrist pressure, but never force them. The body of a Williams sight is made from lightweight aluminum alloy, which can strip if you overtighten the steel screws. A snug fit provides plenty of friction to hold your zero through heavy firearm recoil without pulling the soft internal threads.

Can I use liquid thread locker on Williams peep sight screws?

Avoid using permanent or medium-strength thread locker on the fine adjustment screws or sliding locks. If you notice the base screws that mount the sight to your rifle receiver backing out under heavy recoil, you can apply a tiny dab of low-strength, removable thread locker to those mounting screws only. Never apply thread locker to the elevation or windage adjustment threads, as it will gum up the mechanism and seize the adjustments.