Sight Aligment Error

[700VLSguy]

I'm trying to find the word that describes how a small error at the muzzle is amplified at a greater distance. For example, being off 1/16" at the muzzle could end up being several inches downrange.

I've only seen this word once and I've tried digging through some of the other threads to see if anyone else has mentioned it.

 

[308pirate]

Trigonometry is the word you're looking for

 

[Ankeny]

It's not hard to figure out, but you also need to know the barrel length in order to determine minutes of angle or mils.

 

[Conaso]

Using a KISS principle - assuming perfect environmental conditions and a 36" sight radius (black powder days), moving the muzzle .05" would result in shifting the bullet strike .5" at 100yds or 5" at 1000yds. Shortening the sight radius increases the bullet deviation, i.e., 18" sight radius doubles the deviation, e.g., 1.0" at 100yds.

How'd I do?

 

[Glong96611]

The term you are looking for is angular deviation.

 

[C.R. Adams]

to get a "good enough for government work" answer at reasonable distances, all that is required is to set up two fractions with one unknown and solve for it. treat the rear butt of the rifle as a starting point, measure the inches from there. so let's say, it's 52" from butt to end of barrel and you want to know what 1/2" movement of the muzzle would make at 100 yards. .5/52 = z/100.................. convert the 100 yards to inches (or the 52" to yards) .5/52 = z/3600...... solve for z.................... .5 x 3600 = 52z ...............1800 = 52z....................1800/52 = z................34.6"=z