Tuesday, April 23, 2013

Precision and Accuracy

Currently trained as an engineer, I have had the distinction between precision and accuracy driven into me. But I've noticed that in the shooting community that the usage of one is neglected or that they are used interchangeably.


Picture from http://www.carolina.com/teacher-resources/Interactive/accuracy-versus-precision-beanbag-toss/tr10646.tr
This is unfortunate, since the distinction is important, even in shooting.
Precision is a function of the rifle's build qualities and the ability of the shooter. Precision is the ability to fire bullets within a certain distance of each each other (normally a good benchmark is 1 MOA see below). This is normally referred to as "a grouping".

Accuracy is something quite different. An accurate rifle setup will deliver bullets with the center of the shots being the intended target. An inaccurate rifle setup is the result of the sights or optics not being aligned with the barrel. Accuracy has more to do with whether the bullet struck close to the target or not ("closer" being subjective), where precision involves whether the rifle is able to deliver a bullet to very close to the same location again and again.

Often an "accurate" rifle is actually precise. The user adjusts the optic/sights to make the setup accurate by definition, but the gun is capable of shooting bullets nearly on top of each other. Obviously the goal of any shooter is to be precise and accurate, even though most would just say accuracy is the goal.

Precision and accuracy together produce repeatability. Th ability to hit small targets consistently and reliably is the object of almost all shooters.

With this post, I wanted to bring up these definitions, no matter how trifling they are. I find it odd that the two distinctions aren't used more often in the shooting world, given the fascination with precision rifles.

***
Roughly speaking a 1 MOA rifle means it can reliably hit 1" at 100 yards, 2" at 200 yards, and 5" at 500 yards.
A 3 MOA rifle would hit 3" at 100, 9" at 300, and so on.
A sub-MOA rifle would hit smaller that an inch at 100 and smaller than 4" at 400 yards.

One MOA is considered by many to be a fine rifle and sub-MOA rifles are considered superb.


No comments:

Post a Comment