Bill Calfee
Gun Fool
How a muzzle device works to enhance accuracy
CYA friends:
It's been almost 30 years since I spent a hard year of my life testing, and all the finical resources I could gather, to develop the muzzle device we all take for granted today in the world of accuracy.
The process is well documented in my book, "The ART Of Rimfire Accuracy".
And after almost 30 years now, a bunch of folks are still confused as to what a muzzle device does, and why.
The parallel node:
CYA friends, if any of you folks, who don't already understand, would like to run a simple spearment about barrel vibrations, then I'm going to make the process as simple as humanly possible.
The first thing you'll need is a length of 3/32" rod, welding rod is perfect.
And you'll need a bench vise....
Clamp one end of the 3/32" rod in a bench vise, with exactly 21-1/2" sticking out of the jaws of the vice.
The other end floats of course.
This replicated a gun barrel with one end attached to an action, bedded in some sort of stock, with the other end free floating.
Take a felt tip marker and place a mark exactly 4-3/4" back from the end of the rod.
This is the location of the parallel node in a 21-1/2" length of 3/32" rod, with one end clamped and the other end floating.
Here's a couple pictures:
_____________________________
The above picture describes how to cause the rod to vibrate so you can get a good visual look at how the parallel node acts.
The rod will vibrate by other methods, but, this is the best way to keep it stationary so you can see exactly what's going on.
_______________________________
CYA friends, over the next few days I'll discuss the parallel node and its length.........
Plus, the fact that no matter how fast you cause the rod, or barrel, to oscillate, the exact center of the parallel node does not move closer to, nor further away, from the end of the rod.......or the end of a naked gun barrel.
This is why once you get the exact center of the parallel node to the exit of the crown, by using a properly weighted and positioned MD, ahead of the crown, the exact center of the parallel node remains at the crown forever.....
In other words, the muzzle is stopped.......literally, physically stopped.
The length of the parallel node changes, depending on the severity of the barrel oscillations, but, once the muzzle is stopped, the exact center of the parallel node remains at the exit of the crown forever, no matter how severe the barrel oscillations.
More later.
Your friend, Bill Calfee
________________________
PS:
CYA friends, once you master getting the rod to vibrate so you can see what's actually taking place, studying barrel vibrations becomes a fascinating endeavor...
Please keep something in mind; the parallel node location I've shown you is only for a 21-1/2" long, 3/32" rod.
A 21-1/2" length of 1/8th diameter rod has a different parallel node location, just as do different sized gun barrels.
Please keep something else in mind:
Once you master getting the rod to vibrate so you can see what's happening, you need to remember that the visual vibrations you're seeing are several hundred times greater, by actual measurement, or maybe even a thousand times greater, than that which a rifle barrel actually vibrates.
For instance:
When you watch the vibrations die away, and see the length of the parallel node increase, imagine what that increase in length is on a rifle barrel.
And you'll also see, as the vibrations die away, and the length of the parallel node increases, that the exact center of the parallel node does not change.....
No matter how fast you cause that rod to vibrate, the exact center of the parallel node remains 4-3/4" from the end of the rod.
The same thing happens with a rifle barrel.......bc
CYA friends:
It's been almost 30 years since I spent a hard year of my life testing, and all the finical resources I could gather, to develop the muzzle device we all take for granted today in the world of accuracy.
The process is well documented in my book, "The ART Of Rimfire Accuracy".
And after almost 30 years now, a bunch of folks are still confused as to what a muzzle device does, and why.
The parallel node:
CYA friends, if any of you folks, who don't already understand, would like to run a simple spearment about barrel vibrations, then I'm going to make the process as simple as humanly possible.
The first thing you'll need is a length of 3/32" rod, welding rod is perfect.
And you'll need a bench vise....
Clamp one end of the 3/32" rod in a bench vise, with exactly 21-1/2" sticking out of the jaws of the vice.
The other end floats of course.
This replicated a gun barrel with one end attached to an action, bedded in some sort of stock, with the other end free floating.
Take a felt tip marker and place a mark exactly 4-3/4" back from the end of the rod.
This is the location of the parallel node in a 21-1/2" length of 3/32" rod, with one end clamped and the other end floating.
Here's a couple pictures:
_____________________________
The above picture describes how to cause the rod to vibrate so you can get a good visual look at how the parallel node acts.
The rod will vibrate by other methods, but, this is the best way to keep it stationary so you can see exactly what's going on.
_______________________________
CYA friends, over the next few days I'll discuss the parallel node and its length.........
Plus, the fact that no matter how fast you cause the rod, or barrel, to oscillate, the exact center of the parallel node does not move closer to, nor further away, from the end of the rod.......or the end of a naked gun barrel.
This is why once you get the exact center of the parallel node to the exit of the crown, by using a properly weighted and positioned MD, ahead of the crown, the exact center of the parallel node remains at the crown forever.....
In other words, the muzzle is stopped.......literally, physically stopped.
The length of the parallel node changes, depending on the severity of the barrel oscillations, but, once the muzzle is stopped, the exact center of the parallel node remains at the exit of the crown forever, no matter how severe the barrel oscillations.
More later.
Your friend, Bill Calfee
________________________
PS:
CYA friends, once you master getting the rod to vibrate so you can see what's actually taking place, studying barrel vibrations becomes a fascinating endeavor...
Please keep something in mind; the parallel node location I've shown you is only for a 21-1/2" long, 3/32" rod.
A 21-1/2" length of 1/8th diameter rod has a different parallel node location, just as do different sized gun barrels.
Please keep something else in mind:
Once you master getting the rod to vibrate so you can see what's happening, you need to remember that the visual vibrations you're seeing are several hundred times greater, by actual measurement, or maybe even a thousand times greater, than that which a rifle barrel actually vibrates.
For instance:
When you watch the vibrations die away, and see the length of the parallel node increase, imagine what that increase in length is on a rifle barrel.
And you'll also see, as the vibrations die away, and the length of the parallel node increases, that the exact center of the parallel node does not change.....
No matter how fast you cause that rod to vibrate, the exact center of the parallel node remains 4-3/4" from the end of the rod.
The same thing happens with a rifle barrel.......bc
Last edited: