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View Full Version : Rifle Zeroing & Trajectory in simplest words



Skeeter60
25-08-2009, 01:03 AM
Let us hear the simplest correct explaination

AzamAgha44
25-08-2009, 08:53 AM
Line of Sight. Straight line from your eye to the target.
Axis of Bore. Imaginary line passing through centre of bore to the target
Trajectory. Path in the air that a projectile takes from muzzle of a gun to the target
Bore Sighting. Process of alligning axis of bore with line of sight.
Zeroeing. PROCESS OF ALLIGNING LINE OF SIGHT WITH TARJECTORY

MIdreesTaj
25-08-2009, 04:43 PM
1- anything having mass is pulled down towards earth, so as bullets. they come down to ground in a gradual decline.
2- Also air drag and winds deflect their paths to sideways.

Therefore to keep the impact of bullet on an intended area, we might need to adjust the muzzle up/down left/right accordingly to send the bullet inside the TARGET! these adjustments are done and hence called ZEROING!

Zeroing could be done to an Optical sights(riflescopes) or Iron sights(adjustable).

The natural phenomenon that acts on a bullet when it leaves the Barrel, i.e gravity, wind drag etc, resulting in change of the path of bullet, AWAY from a straight line, is called trajectory.

KageFox
26-08-2009, 07:58 PM
Any way to "zero" fixed sights?

Sialvi
26-08-2009, 11:20 PM
basically "zero" means zero errors. iron sights can be zeroed by adjusting windage and elevation.

Hamid
27-08-2009, 01:07 AM
Line of Sight. Straight line from your eye to the target.
Axis of Bore. Imaginary line passing through centre of bore to the target
Trajectory. Path in the air that a projectile takes from muzzle of a gun to the target
Bore Sighting. Process of alligning axis of bore with line of sight.
Zeroeing. PROCESS OF ALLIGNING LINE OF SIGHT WITH TARJECTORY

Nothing can be more concise than this. Good job Agha Sahib!

Enigmatic Desires
27-08-2009, 01:56 AM
Succinct description Ahga Sahib

Conceal Carry
27-08-2009, 12:10 PM
http://img104.imageshack.us/img104/6108/33512536.gif (http://www.postimage.org/)

Bore Centerline - This is the visual line of the center of the bore. Since sights are mounted above the bore's centerline and since the bullet begins to drop when it leaves the muzzle the bore must be angled upwards in relation to the line of sight so that the bullet will strike where the sights point.

Bullet Trajectory - This is the bullet's path as it travels down range. It is parabolic in shape and because the line of the bore is below the line of sight at the muzzle and angled upward, the bullet's path crosses the line of sight at two locations.

Critical Zone - This is the area of the bullet's path where it neither rises nor falls greater than the dimension specified. Most shooters set this as 3" to 4" from the line of sight, although other dimensions are sometimes used. The measurement is usually based on one-half of the vital zone of the usual target. Typical vital zones diameters are often given as: 3" to 4" for small game, and 6" to 8" for big game and (Gasp!) anti-personnel use.

Initial Point - The range at which the bullet's trajectory first crosses the line of sight. This is normally occurs at a range of about 25 yards.

Line of Sight - This is the visual line of the aligned sight path. Since sights are mounted above the bore's centerline and since the bullet begins to drop when it leaves the muzzle the bore must be angled upwards in relation to the line of sight so that the bullet will strike where the sights point.

Maximum Ordinate - This is the maximum height of the projectile's path above the line of sight for a given point of impact and occurs somewhat past the halfway point to the zero range and it is determined by your zeroing range.

Maximum Point Blank Range - This is the farthest distance at which the bullet's path stays within the critical zone. In other words the maximum range at which you don't have to adjust your point of aim to hit the target's vital zone. Unless there is some over riding reason to the contrary shots should not generally be attempted much past this distance. In the words of the Guru, "It is unethical to attempt to take game beyond 300 meters." If you do, you should write yourself a letter explaining why it was necessary to do so. An approximate rule of thumb says that the maximum point blank range is approximately your zero range plus 40 yards.

Mid-range Trajectory - This is the height of the bullets path above the line of sight at half way to the zero range. It does not occur at the same range as the maximum ordinate height which can be greater.

Minute of Angle (MOA) - A "minute" of angle is 1/60 of a degree which for all practical purposes equates to 1 inch per 100 yards of range. (Actually it's 1.044") Thus 1 MOA at 100 yards is 1 inch and at 300 yards it is 3 inches. The term is commonly used to express the accuracy potential of a firearm.

Zero Range - This is the farthest distance at which the line of sight and the bullet's path intersect.

Taurus
28-08-2009, 05:19 AM
nice info conceal carry and others much simpler

TAREEN
28-08-2009, 08:22 AM
We didn't hear any thing from the expert himself! :)

Conceal Carry
28-08-2009, 12:50 PM
Only qualified and experienced gunsmiths with basic knowledge of geometry with appropriate tools to move fixed sights, not by hammering it out to one side or the other.

Every handgun is sighted at factory to a distance of 25 meters, and every rifle to a distance of 100 meters. (these are industry standards)



Any way to "zero" fixed sights?