The way I am visualizing the dampening of the harmonic vibrations is that the damping action lowers the peaks or amplitudes of the sin waves, and elongates the waves as well. So, the lower the amplitude of the waves, the easier it is for the muzzle to stay closer to center, and the nodes will be longer and more room inbetween them because the wave is flattened and elongated and the peakiness of the amplitude is clipped. That is the way I think it works, though I am not a harmonics vibrational scientist and why I asked the questions I did when I began trying to understand harmonics, tuners, and how they work. Your experience is interesting to me because you have both the steel weight type tuners, and the one (the PDT) that is supposed to offer a combination of dampening and changing how the nodes behave. Could just be that the weight component of the equations is the more controlling factor than the impact of the dampening technology on the outcome. Its one reason testing the Sorbothane seems interesting to me too.
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Barrel Tuners- Muzzle Breaks- Barrel Harmonics Management
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The way I am visualizing the dampening of the harmonic vibrations is that the damping action lowers the peaks or amplitudes of the sin waves, and elongates the waves as well. So, the lower the amplitude of the waves, the easier it is for the muzzle to stay closer to center, and the nodes will be longer and more room inbetween them because the wave is flattened and elongated and the peakiness of the amplitude is clipped. That is the way I think it works, though I am not a harmonics vibrational scientist and why I asked the questions I did when I began trying to understand harmonics, tuners, and how they work. Your experience is interesting to me because you have both the steel weight type tuners, and the one (the PDT) that is supposed to offer a combination of dampening and changing how the nodes behave. Could just be that the weight component of the equations is the more controlling factor than the impact of the dampening technology on the outcome. Its one reason testing the Sorbothane seems interesting to me too.
Here is one more white paper I found that I like a lot. It's one of the 2-3 best documented science papers on barrel harmonics I have found on the web. They are all in the links in this thread now. This adds to the knowledge bank.
this is a non-secure website, but it didn't cause me any problems.
this is a non-secure website, but it didn't cause me any problems.
I completely agree that tuners are a great tool and make a world of difference. My question is how do you go about load development? Do you load say 5 the same and check ES / SD until you get them within your standards and then load several to "tune" with? I understand ES / SD is a function of combustion but has anyone found them to be affected by the tune?
Rardoin
Well-Known Member
@ka30270 You would perform load development pretending the tuner was not present. Once you have suitable load that has proven out on multiple occasions then you test different tuner positions under different conditions over multiple sessions to see how it affects the grouping. Then, when you find that the load is shooting a little fat, you have an educated idea on which direction and magnitude to adjust the tuner to close the groups back up. With hunting narrow contoured hunting rifle barrels it will be difficult to really see what conditions and a tuner is doing to the load since the smaller barrels will heat soak and affect groups before you have enough data to really determine a trend. If you use a tuner to develop a load you are much more likely to end up with a very narrow tune window on the load that could be expected to go out of tune easily.
nealm66
Well-Known Member
I believe the tuner is just finding the spot in the barrel whip where the bullet is exiting in the same spot each time. I have had good luck tuning light barrels with the rubber things and tuners although the rifles all shot really good with factory ammo to start. It just allows me to shoot a different weight bullet at the velocity that I prefer. I just do a velocity test, check es/ds, as long as it's not too crazy, I roll with it, load up 30-50, shoot 3 shot groups adjusting the tuner until I get the group I'm good with and fire 4-5 more. I'll shoot an extra if I have a flier while adjusting. I shoot at 200 so I can see the spread better. Those rubber things are ugly as hell and almost shameful on some of the rifles I have them on like the weatherby in my profile. I used it to shoot 208 eldm's which worked sweet but they came apart after 450 even at a mild speed. Not sure why but had same problem with the 6.5-300. Maybe the freebore? Any ways, that's my process and experience
I can't believe they had that much knowledge in 1901 about vibrational harmonics in firearms.
That was a 2 year college course the last time I checked
That was a 2 year college course the last time I checked
Great thread!
For those of you who read about Virgil in the Secrets of the Houston Warehouse, know about his idea on a specific barrel length for shooting a PPC round at 100 yds. He dealt with harmonics by using a short fat barrel. From the article: "oversized #7 contour to be used without the rifle exceeding the weight limit for Light Varmint class. The barrel was cut to 21 3/4" and target crowned.
More: "But no bit of information was, Virgil believes, more valuable than a little advice Jim Gilmore passed along. Jim said a barrel MUST be 21 3/4" long for optimum accuracy. That precise length, he stated, sets up a vibration pattern that duplicates well from shot to shot. Virgil faithfully followed that advice on his guns. Anyone who strictly observes the 21 3/4" doctrine will screw off a failing barrel of that length and run a new one under it. Rechambering and rethreading, in order to achieve more pristine lands just forward of the throat, shortens the barrel. Shorten the barrel, spoil the magic length."
An anecdote from the past:
I was talking to the recently retired gunsmiths Dave Miller and Curt Crum of Dave Miller Co. here in Tucson. They told me they had a problem with a custom built 300 Weatherby rifle (their favorite chambering) that wasn't responding to their usual loads. They installed a radial brake on it and it settled down. Who knows if it was the jet blast in all directions or the extra weight at end of barrel that changed the harmonics, either way it made that rifle shoot tight clusters.
While this thread is about tuners it also is about harmonics. I didn't read anything here on action screw tension. There was an article in Accurate shooter a few years ago that addressed this and it pertained to Savage actions.
https://www.accurateshooter.com/technical-articles/savage-action-screw-torque-tuning/
I have experimented with action torque with every rifle I shoot from the lightest sporter hunting rifles to heavy BR rifles and none have savage actions. Most rifles showed a preference for a particular torque. This has to be part of the harmonic reduction process. FYI all rifles I own are bedded with all of most of the barrel floated.
The knowledge we can get from threads like this one run circles around those boring gun/hunting magazines.
For those of you who read about Virgil in the Secrets of the Houston Warehouse, know about his idea on a specific barrel length for shooting a PPC round at 100 yds. He dealt with harmonics by using a short fat barrel. From the article: "oversized #7 contour to be used without the rifle exceeding the weight limit for Light Varmint class. The barrel was cut to 21 3/4" and target crowned.
More: "But no bit of information was, Virgil believes, more valuable than a little advice Jim Gilmore passed along. Jim said a barrel MUST be 21 3/4" long for optimum accuracy. That precise length, he stated, sets up a vibration pattern that duplicates well from shot to shot. Virgil faithfully followed that advice on his guns. Anyone who strictly observes the 21 3/4" doctrine will screw off a failing barrel of that length and run a new one under it. Rechambering and rethreading, in order to achieve more pristine lands just forward of the throat, shortens the barrel. Shorten the barrel, spoil the magic length."
An anecdote from the past:
I was talking to the recently retired gunsmiths Dave Miller and Curt Crum of Dave Miller Co. here in Tucson. They told me they had a problem with a custom built 300 Weatherby rifle (their favorite chambering) that wasn't responding to their usual loads. They installed a radial brake on it and it settled down. Who knows if it was the jet blast in all directions or the extra weight at end of barrel that changed the harmonics, either way it made that rifle shoot tight clusters.
While this thread is about tuners it also is about harmonics. I didn't read anything here on action screw tension. There was an article in Accurate shooter a few years ago that addressed this and it pertained to Savage actions.
https://www.accurateshooter.com/technical-articles/savage-action-screw-torque-tuning/
I have experimented with action torque with every rifle I shoot from the lightest sporter hunting rifles to heavy BR rifles and none have savage actions. Most rifles showed a preference for a particular torque. This has to be part of the harmonic reduction process. FYI all rifles I own are bedded with all of most of the barrel floated.
The knowledge we can get from threads like this one run circles around those boring gun/hunting magazines.
Rather than re-post here's a link to some results I recently had using a tuner for my 300wsm. I basically used the tuner in place of changing seating depth and it worked out well.
www.longrangehunting.com
Barrel tuner results
Wanted to share some results with the kinetic security solutions tuner I picked up a few months ago. I’ll be honest, at first I was a bit skeptical but it’s pretty apparent that the tuner definitely does “something”. In this particular case I was able to find a setting that yielded some...
MikeEzell
Member
I realize this is an old thread but I just came across it in a mostly irrelevant search. Anyway, I just wanted to mention that my centerfire tuners have always weighed right at 7 ounces until I began making a lighter 5 ounce model a couple of years ago. I have made a few one offs over the years, so it's possible that Robin has one of those but it's unlikely because I've only made a very few that were heavier than the standard 7oz model.Robin, did you actually weigh your tuner or get that info elsewhere. That's possible because the rimfire version does weigh about 10 ounces because of the adapter that allows it to be clamped onto rf barrels.
Not arguing at all. Just want clarity on this or to inspect it myself.
I'll read through this thread and see what else I'm missing.
Thanks!!--Mike Ezell
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