Air Rifle – Adjusting and setting up your rifle

Adjusting the length of the rifle stock

Adjusting the length of the rifle stock (including butt-plate) is very important. If it is not adjusted correctly then many mistakes can occur and accuracy can suffer. This can quickly cause confusion unless the shooter understands the consequences when the shots that seem to be “good” may appear on the target as “bad” shots and vice versa.

The correct length of the rifle stock is very individual and depends on many parameters. Length is influenced by the shooter’s shoulders and chest size, by their overall left arm length (for right-handed shooters) including the length of the upper arm (from shoulder to elbow) and the lower arm (from elbow to left hand extended flat as if holding the rifle fore-end).

Other factors also impact it including neck length, hand size, the fit of the rifle jacket, the height of the rifle butt-plate, the position of the “V” of the pistol grip, and distance between the axis of the rifle-barrel (bore-line) and sightline (number and height of spacers).

Achieving the right length of the rifle stock is quite difficult. Take some time — do not hurry. It requires patience and trial and error. After some time the optimum length can change and you may have to revise it by about 0.5 to 2 mm.

Adjusting stock / butt-plate – angle and height

The stock/butt-plate transfers recoil from the rifle to the body. Its adjustment has a large influence on the reaction of the rifle after a shot. If adjustment is correct, the transfer of reaction into the body is always with the same intensity and into the same place. That helps minimize group size and reduce “fliers”.

Adjusting the butt-plate is possible both horizontally and vertically. The butt-plate should be as close as possible to the axis of the rifle in the horizontal (sideways) direction, taking into account chest size, arm thickness and neck length. Moving the butt-plate away from the axis causes inconsistent recoil and follow-through and produces more fliers.

According to ISSF Rules, the butt-plate can be moved up to 30 mm from the barrel axis on either side and must not be parallel with the vertical axis of the rifle stock.

The angle of the butt-plate must keep contact with the shoulder/arm stable and consistent from shot to shot during aiming, firing and follow-through.

Height is determined by the zero point (natural point of aim). If the zero point is high above the target, move the butt-plate down. If it is under the target, do not force the hold — move the butt-plate up.

Adjusting the palm rest

According to ISSF Rules, the palm rest can be moved up to 120 mm below the barrel axis. Adjust it so the zero point of your position is exactly in the middle of the target. The palm rest must be supported by the palm the same way on every shot; otherwise the group will drift away from the ten.

Adjusting the cheek-piece

The cheek-piece helps keep your head in the same place so aiming is comfortable with minimal neck tension. Your head must be in precisely the same place, looking naturally through the diopter to the foresight throughout the shot process.

Cheek contact and pressure on the cheek-piece must be consistent from shot to shot and must not slip. Pressure should be optimal (not too hard) and as close to the axis of the rifle as possible, to avoid disturbing the rifle during the shot, recoil and follow-through.

Everyone has a different cheek shape. Angle and rotation of the cheek-piece should respect that. Prefer keeping the cheek-piece parallel to the center-line and parallel with the rifle axis, or with only a minimal offset. ISSF Rule: maximum distance of the cheek-piece must not be greater than 40 mm from the axis of the rifle.

Adjusting the hand-grip (pistol grip)

The hand-grip of most modern rifles can be adjusted in every direction. Adjusted correctly it helps; adjusted badly it hurts accuracy. According to ISSF Rules, the hand-grip cannot touch your shooting jacket on the left side of the chest (right-handers). This is often a problem with a strongly arched upper body and must be watched by the coach. At major competitions this rule is controlled more strictly.

If the pistol grip touches the jacket: Some shooters file the contact point of the grip; others alter the jacket on the left chest (or both). Moving the grip fully to the right is not optimal — the rifle then reacts more to the weight of the right hand and can cause large errors.

The axis of the hand-grip (front to back) should be as close as possible under the barrel axis and can be rotated slightly left (about 10–11 o’clock) relative to the shooting direction. Remember the maximum width of the fore-end is 60 mm.

Adjusting the position of the trigger

Trigger position has a direct influence on technique and group size. Every shooter has an individual correct position. A coach can see whether the finger is optimal. Aim for about 110° angle of the index finger at the moment of release.

Contact should be approximately in the center of the last segment of the index finger, or 1–3 mm toward the fingertip — places with higher sensitivity and less negative effect on the release. Test different contact positions to find your optimum.

Adjusting the fore-end

Some rifles allow fore-end adjustment. Use it only if needed. The left hand must contact the fore-end always at the same place and with the same pressure, with weight distributed evenly across the bearing surface and minimal discomfort.

You can turn the fore-end slightly left or right, but that changes the centerline and affects the rifle when firing. Incorrect movement leads to poor results. Often it is better not to adjust the fore-end if the current setup avoids bigger mistakes. The goal is a setup (within ISSF Rules) as close as possible to a perfect hold and natural point of aim.

Adjusting any barrel extension

Be careful: the length of the rifle (action + barrel, excluding stock) is limited by ISSF Rules to 850 mm. If there is a tube on the barrel with an integral front sight, adjust the barrel extension horizontally so the sightline is above the barrel axis, not to the side.

Adjusting the diopter, iris and blinder

The iris aperture on the diopter should be opened up to a maximum of about 1.2 mm. More opening reduces aiming acuity; less opening reduces light, the target looks poorly illuminated and aiming becomes less precise.

Adjust the eye blinder horizontally so the left eye cannot see the target and distracting contrast is cut out. Prefer grey, black, dark green or dark blue. Some shooters use a light blinder under a cap so it appears darker in position while keeping good contrast.

Diopter position: Head, cap and glasses must not touch the iris or body of the diopter (ISSF Rules). At the same time keep the diopter as close as practical to the eye (about 30–40 mm). Mark the correct position on the sight rail after testing.

Front sight position and aiming ring size

Select the ring size and fix the tunnel at the correct place on the sight rail. Tunnel length and diameter are limited by ISSF Rules (50 mm and 25 mm). Ring size is commonly between 3.6 and 4.3 mm. Advanced shooters often use 3.7–3.8 mm — that needs excellent stability. Smaller rings improve aiming accuracy only when stability is already high.

Beginners and lower-level shooters often use 4.2–4.5 mm. Rings below 3.6 mm are rarely useful because of weaker stability, acuity or contrast. Ring size also depends on sight radius. On a short junior rifle, 3.6 mm can look similar to about 4.5 mm on a full-length system.

Test A

Test B

Prefer fixing the tunnel as close as possible to the muzzle for a longer sight radius and better accuracy — but only while the ring stays visually sharp. Sharpness of the foresight ring is critical. The distance where sharpness drops is individual and changes with light, age, fatigue and mental/physical condition.

Weight of the rifle

Maximum rifle weight is limited to 5.5 kg. Most makers deliver under 5 kg in basic configuration. Great results have been achieved both just under the maximum and with considerably lighter rifles. Adding weight is a personal decision, but as a general rule it is often advisable — especially for stronger, taller shooters — to compensate physical force. A heavier rifle is less affected by micro-movements from the body and by recoil than a lighter one.

Keep the whole shot process, including recoil and position, under control. If you add weight, the centre of gravity is often best about 1–3 cm in front of where the left hand supports the rifle (this can vary if needed). Add weight as close as possible to the barrel axis to avoid shifting the rifle sideways. Weights on the barrel, inside/on the fore-end (within thickness limits), under the cheek-piece or between butt-plate and stock can improve balance and stability when done carefully.