NRA Probationary Course Unit 8 The Rifle Sights Compiled by Dave Burton.

NRA Probationary Course

Unit 8The Rifle Sights

Compiled by Dave Burton

NRAProbationary Course

Unit 8Introduces:

Minutes of Angle

Vernier Scales

Elevation & Wind Settings

Different types of sighting system

Elevation And Distance

When the rifle is close to the target the bullet hits the centre providing the sights are correctly set to the bore

Elevation And Distance

But:-

further away, the bullet drops due to gravity and air resistance

Elevation And DistanceTo hit the target the front of the barrel must be raised

The longer the range, the more the barrel must be raised

ELEVATION• The further the distance from firer to target,

the greater the angle ‘x’ has to be.

‘x’ is the angle measured on the sight.

x

FirerTarget Target

trajectory

ELEVATION

• Only a small change of angle is needed at the rifle end to make a big difference at the target end

• The angle is measured in MINUTES of angle - (one minute is 1/60 of a degree)

• At 100 yards, changing the sight by 1 minute, changes the fall of shot on the target by 1 inch

Minutes Of Angle

A minute of angle is:

The adjustment of the REARSIGHT

that will cause the POINT OF IMPACT

to move 1 Inch per 100 yards

ELEVATION

• Therefore: Distance 1 minute at the target is:

100yd 1”

200 yd 2”

300 yd 3”

etc.

ELEVATION

1 Minute

200 yds

2 inches

300 yds

3 inches

1 inch

100 yds

Approx elevation To Allow For Bullet Drop Over Set Distances

CHANGE (yards)

RISE BETWEEN RANGES (minutes)

100 - 200 2.0

200 - 300 2.5

300 - 400 3.0

400 - 500 3.5

500 - 600 4.0

Elevation

DISTANCE (yds) RISE (mins)200 – 300 2.5300 – 500 6.5500 – 600 4.0600 – 900 16.0900 – 1000 7.0

This gives us the standard rises between ranges:

Standard Elevation Table for 7.62mm

To Rise from

300 400 500 600 700 800 900 1000

200 2.5 5.5 9 13 17.5 23 29 36.5

300 — 3 6.5 10.5 15 20.5 26.5 34

400 — — 3.5 7.5 12 17.5 23.5 31

500 — — — 4 8.5 14 20 27.5

600 — — — — 4.5 10 16 23.5

700 — — — — — 5.5 11.5 19

800 — — — — — — 6 13.5

900 — — — — — — — 7.5

The Elevation Vernier

20

0

40

5

0

20

0

40

5

0

20

0

40

5

0

0 1 4

Elevation Vernier Settings


Set at 6 minutes of elevation

The Wind Vernier

The Effects Of Wind On The Bullet

Target

F P

StillAir

Target

F P

StillAir

Range Flags/Wind Speeds

Light 2 mph

Gentle 4 mph

Moderate 8 mph

Fresh 12 mph

Strong 16 mph

Very Strong 20 mph

The Wind Scale

The Wind Scale

0

20 0 20

505

2 LEFT

20 0 20

505

3 RIGHT

20 0 20

505

Set at 8 min left

The Wind Scale

Sight Systems

Different target shooting disciplines may involve different types of sights eg.•Telescopic sights (F and Match class)•Leaf sights (Older military rifles)•Buckhorn sights (Gallery rifles)

“Service” Rifle Sights

Note the different method of sight adjustment

Telescopic Sights

Telescopic sight adjustment may be in the opposite direction to that of target sights

Leupold Sight

Telescopic sight adjustment may be

in the opposite direction to that of

target sights

Tasco Sight

NRA Probationary Course

Compiled by Dave Burton

NRA Probationary Course Unit 8 The Rifle Sights Compiled by Dave Burton.

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Transcript of NRA Probationary Course Unit 8 The Rifle Sights Compiled by Dave Burton.