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Old June 1, 2009, 01:15 AM   #7
Major Dave (retired)
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Join Date: March 12, 2008
Location: Between Dallas and Shreveport, LA
Posts: 569
Bullets never rise - they only fall

"... The bullet follows a curved path, first going up from below, passing thru the point of aim, rising up above it..."

NOT TRUE!!! A bullet never rises above the Line Of Bore.

Wogpotter - envision a straight line from the muzzle to the bullseye. This is called "Line Of Bore", or LOB. LOB is initially below Line Of Sight by the amount equal to the difference between the center of the bore and the center of the objective lens of the scope. These two lines are perfectly straight, with no curvature.

The bullet, NEVER RISES above the LOB, but immediately upon exiting the muzzle, begins to drop below the LOB, due to the pull of gravity. It always drops further and further below the LOB, as the distance from the bore increases and gravity pulls the bullet downward. As the bullet loses speed, the influence of gravity becomes greater, resulting in an ever increasing downward curve in the trajectory (flight path) of the bullet. This is referred to as "non-rigidity of the trajectory", Therefore, the greater the distance to the target, the steeper the trajectory.

So, how come the bullet crosses the Line of Sight twice? (It does do that, after all.)

The answer is that the scope is adjusted (internally) so that it looks downward at a steep enough angle to cross both the Line Of Bore, and the trajectory, initially at about 25 yards, and then converges to intersect the trajectory precisely at the range for which the weapon is zeroed. That's the definition of a "zero". Therefore, the trajectory of the bullet is below the Line of Sight to about 25 yards, above the Line Of Sight from about 25 yards, to the zero distance, below the Line Of Sight at any distance beyond the zero distance, and NEVER RISES above the Line Of Bore. The bullet is above the Line Of Sight, briefly, only because the Line Of Sight is angled downward, NOT because the bullet rises.

Sketch it out on a piece of paper. When properly sketched, Line Of Bore will be above the target, Line of Sight will start above Line Of Bore, go downward to cross both LOB and trajectory, and terminate at the target exactly where the trajectory terminates. The trajectory will begin at the muzzle, remain almost flat, but slightly below line of bore for about 2/3 rds the distance to the target, then "droop" the final 1/3 distance to the target, hitting it precisely in the center, exactly where the Line Of Sight terminates.


So, the OP asked if the accuracy would suffer if he used high rings to achieve a good cheek weld when he was shooting. The answer is that the accuracy is not affected. His scope, when zeroed, with the high rings, would simply be tilted (internally) further than it would be with low rings.
Using high rings, if the shooter tried a long shot (400 yards and beyond), he would need a greater amount of holdover than a zero using low rings.
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Last edited by Major Dave (retired); June 1, 2009 at 01:27 AM. Reason: Add info
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