Rifle Nodes
BY Herschel Smith
Many commonly-used terms in the shooting community aren’t widely understood or used in a consistent context, so it’s important to define what we are talking about. The technical term “node” refers to the points on a wave at which the amplitude or displacement is the smallest. In terms of a vibrating object like a rifle barrel, it’s the point at which the vibrating barrel moves the least. A rifle barrel does have nodes as it vibrates during and after a shot is fired, but when someone refers to “finding their rifle’s nodes,” they’re referring to finding the charge weight and velocity that causes the bullet to exit at or near that node or dead spot in the barrel’s movement as it vibrates back and forth.
[ … ]
When I brought up the subject with Shooting Editor John B. Snow, he said that all his data had supported the idea that chasing nodes doesn’t gain you anything. He and other high-level shooters at team events will even tailor their loads to target matching velocities to simplify drop and windage calculations between shooting partners …
He goes on to discuss a number of interesting points – interesting to me, at least, including whether a 3- or 5-round group is really sufficient to show anything of value. I agree with him. It’s not.
This is true for a number of reasons. Let’s move past the implications of chaos theory. Atoms are moved by Brownian motion. Atoms bond together to form crystalline structures. Crystalline structures can slip against each other. The barrel heats as it is fired. This motion changes each time the barrel sustains a round being fired through it.
There are other effects as well. This all means that a 3-round group isn’t really relevant for anything much except inflating your ego. Now, let’s move past the issue of repeatability due to physical effects and ponder whether the action of a bullet travelling down a barrel is governed by a deterministic process or a Monte Carlo process. That is, if you could exactly measure the grains of powder charge, exactly govern the bullet weight, and exactly control the barrel temperature, each and every time a rifle is fired, would the bullet go into exactly the same hole each time? Or would the group behave as a random process in which the grouping is always described by a standard distribution?
I think about things like that.
I prefer to just do the best I can and shoot the best equipment I can find within reason. I am not a performance precision rifle competition shooter. If I was, I would probably do the things he’s talking about.
But I wouldn’t assume that a 3-shot group meant much of anything.