Bore Axis: A Force to Reckon With
When reading reviews about the latest and greatest firearm on the market, the term “bore axis” is often used to describe a part of the gun’s operational system. The gun may be characterized as having a bore axis that adversely affects accuracy or as having a low bore axis that makes the gun easy to shoot.
Basically, bore axis is a great example of Newton’s Third Law of Motion, which states that for every action, there is an equal and opposite reaction.
The force of the bullet discharging and speeding through the barrel creates an opposite force backwards until it is stopped by your hand on the grip.
At that point, the hand acts as a fulcrum for the barrel and the backward force continues upward, causing what is known as muzzle flip.
This all may be all well and good, but how does Newton affect the operation of your favorite concealed carry piece? Author Tamara Keel explains how the bore axis of your gun can affect accuracy in her article “Bore Axis of Evil” at USConcealedCarry.com:
“The higher above your hand the lever of the barrel is, the more mechanical advantage it has, and the harder it becomes to control this motion. Therefore, gun designers try to find ways to bring the barrel line, or ‘bore axis’ down closer to the shooter’s hand.” (Read more at USConcealedCarry.com)
Pistols generally have lower bore axes than revolvers because revolver barrels tend to sit higher above the shooter’s hand due to the extra height imposed by the cylinder. Some revolver companies are attempting to rectify the issue. Chiappa Firearms created a new .357 Magnum that’s designed to fire from the bottom cylinder rather than top, basically eliminating the revolver bore axis problem.
The Chiappa gun is the latest in a series of modifications attempting to alleviate the bore axis problem. Early 1911 model grips were too high and resulted in hammer pinch. Colt modified this with a rounded spur on the hammer.
Over time, local gunsmiths incorporated upward machined “beavertail” safeties, as well as reducing the area where frame and trigger guard met to allow the hand to be higher on the grip. Eventually, these modifications became standard-issue on all 1911’s and helped it earn its reputation as a low bore axis weapon.
The easiest solution to bore axis issues is simply adjusting your grip. Owners of the Smith & Wesson “Centennial” revolvers discovered that they were able to significantly reduce the bore axis by simply moving their hand higher up on the grip. Try it on your favorite conceal carry weapon and notice the improvement in comfort, control, accuracy, and reduction in time between shots — a crucial element in a self-defense scenario.