Barrel Harmonics Testing - Part 1
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- Опубликовано: 8 сен 2024
- It's finally time for our barrel harmonics testing. We shoot groups with 10 muzzle devices and try to spot any trends.
Barrel Harmonics playlist (TiborasaurusRex video and others): • Long Range 101 Part 7 ...
Our test devices:
The Lump 25oz
Krinkov Style Brake 9.1oz
Precision Armament M11 5.6oz
Harrell's Precision Tuner Brake 5.1oz
DPMS Miculek Brake 4.1oz
Silencerco Flash Hider 3.4oz
Precision Armament M4-72 3.1oz
Procomp 762 3.1oz
VG6 Gamma 65 2.4oz
LimbSaver Sharpshooter X-Ring Barrel Deresonator 1.1oz
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UPDATED 09/27/2018 - All links have been removed to comply with RUclips content policies.
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Been watching your videos for about a year. Sometimes I see a fly crawling on your target always find myself thinking do it dude shoot the fly.
Inspirational.
From how I understand this, the main effect on accuracy, assuming we have consistent timing for exit of the bullet out of the muzzle, is minimizing the effect of the high temperature, high velocity gasses behind the bullet exiting the muzzle on the bullet. This is also the reason muzzles are crowned, and all barrels are crowned. The suppressor results do make a lot of sense as this has the largest dispersion of the gasses behind the bulled and will prevent this from having any effect on the bullet after leaving the muzzle. Shooting multiple powder charges with each device (as you did with the suppressor in previous content as well as the beginning of this) does, reasonably well for a real world test, eliminate some of the variables with differing weights and configurations of the devices you have tested by giving a high probability that one of the loads tested will have the correct harmonics for the configuration. With consistent harmonics ( not necessarily powder charge) this would be a good way to observe how the gasses exiting the barrel would effect the path of the bullet, as these forces are the first thing that acts on the projectile outside of the (relatively) closed system inside the barrel.
Just to say as well, I have been watching your channel for almost two years now, and as a young hand-loader, both in age and experience, and the information and honesty in your content is something that I look forward to every day. Thank you for the effort you put in to this, it does make many of our lives better for 10-60 minutes at a time!
I like your thinking about using a break with limb saver in tandem. The key to the limb saver is going to be where it ends up on the barrel. A very small move forward and backwards will change the harmonics. I've tuned barrel harmonics this way with airguns and subtle changes make huge differences downrange. Since you won't have a micrometer like on the Harrell break you'll have to find other ways to determine it's final location, especially if you ever have to remove it.
Absolutely loved the design of experiments. What a wonderful job you did. Obviously there is a direct correlation of weight to point of impact shift. I would love to see how the grouping would change by adding a secondary factor such as using the Limbsaver with the Silencerco flash h hider. Perhaps the addition of a second factorial would enhance the test results. I suspect that the Limbsaver device will need aditional movement to find the sweet spot.
Rule #1 for testing: "if it appears stupid, but it works, it isn't stupid"! The lump supports your weight theory. The adjustable Harrell's supports moving the bullet departure point to find the optimal distance. While all do not change departure fm your threads and perfectly cut target crown, they all have slighly different shapes and dimensions that affect the bullet as it transits the space inside the device. Which was the most comfortable to shoot of the best group producers?
Wow. That's alot of info. Thanks for the epic. I'm still chewing on all those results. Can't wait to hear what everyone else is thinking
same here funny how stuff some times works out
I have been in love with my A-Bolt BOSS rifles in .308 and .300 WM for these very reasons for 25 years. Actually, the best results are making the barrel vibrate at the same frequency so the bullet exits the bore and crown at the same point of the vibration arc eaxh time for that bullet weight. S/F
EC tuner is an amazing device and can be used with a brake
Would like to see you slide that limbsaver up the barrel like an inch shoot it then another inch shoot etc using same ammo setup
Added weight will dampen vibrations, yes. The suppressor and the lump weigh the same, but the added weight on the end of the barrel has it's own moment as it relates to the mounting points of your receiver in the stock. That will lend towards the Shockwave Theory you mentioned in the beginning of the video as well as the physical weight and length of the barrel. As you know, a longer barrel generally produces better accuracy for the most part. The suppressor extends the pressure wave behind the bullet and tapers it off versus blasting it out behind the muzzle crown. I mentioned in your 223Rem video that the muzzle crown might not be uniform on the WOA barrel. Not necessarily messed up, but not perfectly uniform like a highly prepared bench rest rifle.
I wonder how the pressure wave would react in a flow through suppressor like a OSS. On my AR10 I went from a Battle comp to the lantac dragon my groups jump up by 1/2” or 3/4 of an inch pending on bullet weight.
Longer barrels are not more accurate. Usually shorter barrels are due to less harmonic whip.
Well I guess that means we need to reduce the number of variables a little. I have the material to make a 3/4 Lump, 1/2 Lump and a 1/4 Lump. Heck I'll even toss in a 1/2"-28 x 5/8"-24 thread adapter so you also test the Lump family on your .223. I'll try to get them made and mailed out by Monday.
That would be awesome but it sure sounds like a lot of work. I'd be happy to buy these from you rather than continue to mooch. Time isn't cheap and I'm sure you'd much rather spend it on the range!
I design experiments for a living and I agree. This set of shots tested a lot more than just the weight. How about just hanging regular weights off the top of the barrel? Might have to create a way to secure the hanging part to the barrel better. Maybe that can be machined?
Don't worry about the cost. I do machining as a hobby, and shoot for a hobby, and watch youtube as a hobby. So don't worry about it.
Awesome! On behalf of the community, thanks Dave.
Dave D thanks. Your a good fellow :-)
The mental determination to solve problems.
I give you an IQ of 160 . Congratulations an thanks.
Finally!!!! My wife waits all week to watch the Walking Dead when it's on. I wait to receive my notification bell that Johnny's Reloading Bench has a new video. Thank you for taking the time to conduct this test and hold down a full time job. Your the man Mr. Johnny. Have an awsome day sir.
"The more I talk, the dumber I sound" - believe me Sir, that is the case for the VAST majority of individuals - it's not just you! In fact, I'd go so far as to say that the more you talk, the SMARTER you sound because you rationalise things carefully and "think out loud" - you don't just regurgitate other people's ideas. Experimentation is the key to learning. To my tiny brain, your results really do make sense: the mass of the object is one of several factors that help dampen or regulate barrel harmonics. Some of them (like the "three-pronged" flash hider or the rubber dampener are almost certainly oscillating themselves and by chance they are working in harmony with the barrel. A thoroughly fascinating series of experiments.
Your hypothesis ISN'T garbage. It's quite sound, but your testing wasn't adequate. Harmonics are sine wave vibrations. And those waves will alter frequency and amplitude from one load to another, and one barrel to another. Simply adding weight to the end of the barrel is a sound start, but only a start. Change the weight, and you change the waves. Change the OAL and you change the wave. Your goal should be to have the bullet leave the muzzle at the same part of the wave each time. In other words, tune the barrel whipping to the individual load.
Stiff heavy barrels were successful simply because the sine wave amplitude is very small - i.e. small whipping motions, and thus demonstrably more accurate. Browning's Boss was a move in the right direction, but wasn't as successful as it should have been because it was finicky to tune by the average person. But I think YOU should get one and explore it's possibilities. And I'd like to see you add some kind of length adjustment to your silencer to see if you can get even more accuracy using it.
Kirk Boswell really like your suggestion and agree with it... As we play with .01-.03 etc with out powder grains some of the devices you have used are compatible with those lines, the limbs aver, the thing with little holes and "dial nut" and the ones in the same line are just like our powder measure, you can play with them a bit more or less till you fine tune for your barrel harmonics/whipping. #johnny'sreloadingbench don't give up or consider yourself "confused" we all deal with things we don't know yet and learn sometimes take time and experience. I do LOVE your work, has been hard to hang around for a whole week waiting for your videos, it is TORTURE! LOL! Don't ignore the "muzzle breaks" but they are devices to tame the recoil even though they will tune your harmonics if in a weight close to the optimum barrel whip. God bless my friend, till best time... I really hope not long... Thank you again for the great work.
I had the opportunity to meet Ted Gaillard, a great barrel maker who happens to live close to my home growing up. He described barrel harmonics similar to the wave you mentioned. He said barrels whip or vibrate in a figure 8 or infinity pattern. Said the BOSS system was designed to have the bullet exit the barrel at the top or bottom or left or right edges of the 8 or infinity sign. At that point the barrel whip and muzzle was the slowest, and thus the bullet would land more consistently. So it’s not a function of weight per say, but more tuning the barrel vibration at it’s slowest point when the bullet is released from the barrel.
The goal is to have the bullet leave the muzzle at the peak or valley of the wave. That is when it is moving the least.
Barrel tuning has been around for 100 years. We used to grind off the end of barrels and recrown them over and over untill we got a good tight pattern. the "shockwave" moved in a signwave type pattern and you have to time the exit of the bullet from the barrel at the sweet spot. Putting a supressor on a barrel may or may not change the group size. It depends on what the harmonics are changed to by putting the suppressor on. It could actually make it better. Lots of things effect accuracy.
Stocks vibrate against barrels. A big weight on end of barrel dampens the vibrations because it has to move more weight. It's why glassing beds and barrel springs work to cut down on vibrations.
Something to consider for your hypothesis - I once read an article by Patrick Sweeney about the effect both barrel harmonics and exiting gas turbulence had on accuracy. While you don't want an erratic and unpredictability whippy barrel, he said the bigger contributor to accuracy was reducing the gas turbulence. I suspect this is why there isn't any direct correlation between accuracy and weight of the muzzle devices, but rather you are seeing the best accuracy from the devices which do best at reducing turbulence (i.e., the lightweight Silencerco flashhider). Based on your past accuracy tests, I'd say your Thompson Center has a fairly consistently harmonic barrel, so I think your hypothesis will be much less confused if you test various devices to see which ones do the best job of reducing turbulence to give you the best accuracy. Wilson Combat and Daniel Defense have a couple muzzle devices which come to mind.
As with pretty much everything in shooting sports its a game of thousandths of inches and tenths of grains. Your test does a great job of showing muzzle devices impact accuracy period. I think you’ve also demonstrated that its not necessarily true that more is better. I think your testing shows that tuning with dampening or muzzle devices is going to be the same game we are already used to playing......very small increments. Grams vs ounces kinda small.
As fast as your bullet is, the sound velocity through steel is around 16,000 fps. After watching, I was impressed with the limb saver. Weight is obviously not the defining factor here, otherwise a bull barrel would be the obvious choice. Going back to the velocity of sound through steel, the explosion that launched the bullet sent an energy wave through the barrel. It will travel back and forth until all energy is dispersed. The barrel will reverberate not only in "to and from" motion but also in a circular/ radial pattern trying to dissipate the energy. This energy was near 30,000 psi, while much transferred to the projectile, the remainder transferred into barrel harmonics. The rubber has a tremendously different sound velocity, and it's low weight induces less "character" than the metal counterparts. So it absorbs some of the energy and returns a little less back to the barrel but at a delayed effect which causes interference and reducing the barrel oscillation with each pass of waves. Not a new concept, but a decent one for this application. Only draw back is heat. For the "aggressive" shooter, you may wind up with some smoldering rubber dripping from your barrel.
I have a Gamma 6.5 on my Grendel. It definitely tightened my groups up a 1/4". I also have a Pro Comp on a Voodoo Innovations/Adams Arms barrel that is amazingly accurate.
David Koetting I agree, they both shoot well for me on various rifles, that was why I sent Johnny those 2 for this testing. Glad he is going to give the SF ProComp a second group!
You leave us with this lot and "hope" we'll join you for part 2? HAHAHAHA!!!! We got no choice mate, lmao!! You've left us hanging exactly the same as you. Of course we'll be watching!!
A couple of things that you can try if you like, you shot 5 round groups. The first thing is to measure you best 3 shots of each group and compare them. The next thing, pick the mean POI for each test and measure the the best 3 shot groups for each attachment and see which correlates best to the open 5 shot groups.
You are conducting excellent tests, and they've been bloody brilliant to watch!
Thank you for the work you do, absolutely brilliant!
Cheers from down under :)
Pilot McBride - I agree with you on the shot groups. Do 3 shot groups to find the set ups that warrant further testing and/or refining. That would be an excellent way to pare things down a bit, and use 5 shot groups to test those selections. Yes.
I think the silencerco, with it's extended prongs, they acted as tuning forks, isolating a certain range(s) of frequency and possibly converting them to soundwaves, thus lowering the amplitude of that/those frequency(s) the prongs vibrate at. Same concept as the rubber limbsaver buffers
Hypothesis. The word that identifies actual science. Thank you Johnny.
most anticipated video on JRB i'e ever couldn't wait to watch
Johnny, thanks for starting this. Like someone below said, it's weight and gas distribution that both affect the barrel and bullet.
Since the silencer seems to help EVERY barrel, I think it's safe to say that the way a silencer reduces gas pressure as it exits and that that is the best way to keep projectile flight the same every shot.
I'm planning on doing some similar testing. On uppers I put together myself, I plan on starting with barrel nut torque specs. Once I have the best group from torque, I will add the limb saver. Once I have that combined best group, I will try the various muzzle decices.
I don't have a supressor, but I think that the brake style (hillman?) with the spiraled hole placement and adjustable weights might gain the best results due to the way it dispels gasses AND gives micro variants to weight displacement. Therefore, I am considering purchasing a brake light that to include in my own tests.
Hopefully I can put together a video (might not be able to include actual shots like you do) and include at the minimum, showing just the results of each individual step.
Thanks for sharing, you give me a lot of info to consider as I dive into this world. I look forward to part 2.
Thank you for editing out the mechanical nonsense. We don't need to watch you unscrew things, let the barrel cool, or cycle the bolt: Unlike a lot of RUclipsrs, you understand that.
Great video overall, and I look forward to watching more.
I find the most suitable powder that gives the lowest SD in the particular barrel and burns 100% before the projectile leaves the barrel. Then I play with the seating depth in .003" increments to hit a couple of nodes where your groups shrink significantly. Together with sorting the bullet by weight under the bell curve and using a mandrel for equalizing the necks of the shells I get the best accuracy for each of my barrels even without attachments which can be a real nuissance whilst hunting or carrying afield especially during sheep or goat hunting in the mountains. Sure any harmonizers and muzzle weights will flatten the oscillations of a barrel but if you do not hit a node in the vibrations you'll not getting the best accuracy that most barrels can achieve.
Awesome! Going to try one of these with my AR-15 24 inch bull barrell
Wow, very very interesting.. Besides being an airgunner, long range shooter, I also shoot target archery. I mention this because the vibration in the bow (specially the string), considerably affects the arrow fligt.
Some people say that barrel harmonics do not affect the bullet since the vibration occurs after the bullet leaves the barrel. Nothing more wrong...
I agree with some comments about the drag forces that occur after the bullet leaves the barrel. So one possibility could be that the devices change that right outiside the barrel. The CON to this hypotheis is the limbsaver in the 2 positions exposed in the video. (still thinking about this
Congrat´s for this effort!
You get something called a EC tuner, it is made by erik cortina. It works the same as the tuneble muzzle brake exept that it sits behinde you muzzle brake. The tuning is something to understand, as the limbsaver, you can move it in 1/2” back on the barrel and see the deference. You can either tune a load to your rifle or your rifle to a load, say you shoot factor ammo you can tune the barrel to the right node.
I'm watching this video 2 years after you made it because I just ordered the Harrell's Tuner adjustable break. I have exactly the same T/C Compass rifle in 6.5CM with a Silencer Hybrid can which I bought with several accessories including the flash hider you tested. It blew my mind! I need to understand too what's going on. I'm just about to watch parts 2, 3 & 4. I'll be back!
The controlled gases affect the bullets stability and flight. I changed a muzzle flash that was spiraled like a twisted swirl. Then put on a dead air muzzle brake the results improved greatly . No more barrel whip jump nothing. Flat and I don't have any scope picture lose or moving. The swirling flash or break every time lost scope and target had to be required each shot. Also crowned the barrel before the changes smoothing out gases makes big accuracy gains. I have also used the limb saver rubber barrel it works good you have to move it to find the sweet spot little by little bit does help
That limbsaver balanced out the harmonics and the exit of the bullet it looks like RealGood🤙
Think of the end of the device as a shock wave reflector. Anything that breaks up the radial or longitudinal components of the wave into multiple smaller reflected waves will diminish the standing wave that sets up in the barrel. I believe that the light pronged flash hider was effective because it produced at the least two reflections. The first was from the muzzle flash hider interface and the second was a delayed reflection from the tip of the prongs. The resulting fuzzy reflected wave less likely to build into a single strong wave. Remember the waves make multiple trips up and down the length of the barrel before the round leaves.
I believe the forward position for the Limbsvr is only the starting point, the company suggests moving the device rearward in 1/2 inch increments , shooting groups between moves. This is a tuning process for that load in that particular barrel. These devices work quite well. Good luck in solving the problem.
You had my Thumbs Up at "The more I talk the dumber I sound." You just nailed the description of a number of the recreational shooters (and golfers coincidentally) I meet. There's a lot of opportunity for socialization in these two wonderful sports but unfortunately, these interactions often become a platform for the self-proclaimed experts to exploit their agendas. Whether it be equipment, technique or politics, if I want your opinion, I'll ask you. Or, I'll watch a video like this one here.
Great content here.... and great advice to go with it. Thank you.
Stay Strong & Stay Safe,
Boston
1. If you want to test with weight just for weights sake, you need to use a 'lump-like' system where the weight changes, but the effects of gas expansion and its effects on muzzle reaction are minimized/eliminated. 2. With regards to the variety of muzzle devices you have, the weight is the weight and the determining factors with regards to harmonics are a complete load development for each brake tested. (or a combination of that and the next paragraph) 3. When you start talking about adjustable harmonics devices (Harrell's and Limbsaver), you can just about tune any load to a rifle just by incremental testing of setting/position of the device to determine optimum setting/position. My understanding of these devices is that the range of adjustment required for bad to good to bad again (in a sine wave pattern) is not very big at all...maybe 1/8" to 1/4" or even 1/2" to completely define a 'node'. Going from one extreme of adjustment to the other will skip over MULTIPLE nodes and finding the center of a node over the total range is unlikely. Using your choice of non-adjustable brake and a harmonics tuner could be the best combination, with recoil management AND harmonics tuning. It would be nice if the Harrel's device could thread onto a muzzle with enough threads left to 'cap' its installation with a muzzle brake. But since it doesn't, a brake and Limbsaver combo might yeild the best results.Sorry for the long post...I had more to say, but I think I leave it at that.
Consider a sound wave propagating through the barrel. Different weights of device may interact with the peaks and troughs of that wave differently. Some weights are going to damp the wave, others might even add to it by causing resonance. If this hypothesis is correct, it would make sense that the group sizes oscillate as you reduce weight.
I think it would be interesting to plot the muzzle device weight vs the group size. I might actually do that. This test might even allow you to determine your barrel's waveform with this load. Freaking cool!
I am just a lowly geologist, but I do have some background in geophysics, and found this fascinating!
The suppressor is reducing the oscillations,in the same way a heavier gun has less felt recoil.
And the compass is a great rifle. My brother has one in 22-250 which prints the cheapest federal blue box at just over moa and reloads tuned for a heavy barreled savage print sub moa consistently.
From a skinny barreled hunting rifle that's impressive for sure.
Looking forward to the Harrell's for farther testing.
You have done some serious scientific work here. Besides looking at barrel dampening, the weight on the muzzle can in my experience be accounted to muzzle up pressure with weight added to the front end of the barrel. Maybe you can show us some real results by taking into account the pressure applied by the muzzle gas when the muzzle gas escapes the suppressor/muzzle break. this should also affect the muzzle position/point during the period that the bullet exits the muzzle. I guess all of this is a science after all, and such the best grouping was given by the devices with either the highest weight or an evenly distributed gas distribution. I will definitely be watching the trailing videos for more info.
Great work, Sir. Lots of data to filter through. I’ll need to watch this several times and see what jumps out. Thanks for all this hard work. We enjoyed having you stop by our chat last night.
I think you hit the nail on the head with the adjustable.. problem is they're waves you can't see..when you adjust along a linear path, you have sine waves with harmonic highs and lows..so as you turn the tuner dial up and down, you attempt to balance those harmonic waves of distortion..there maybe several choices but it is up to you to find the sweet spot and it takes time and diligence... You've taken on a monster of a subject .. these devices are not plug and play tuners as you know?.. every barrel is different and requires individual tuning ( small incremental increases or decreases) and range time... I wouldn't get frustrated..You could write a book on the subject.. attempting to condense it should be broken up into segments so you can take a deeper dive into how and why each one works the way they do ..pro's and con's? Keep up the good work and keep hammering 🔨 the paper!
I love how you use science to figure out what is really going on keep up the good work
After watching the video, the differences in grouping could also be attributed to the way the gas is redirected with the various muzzle brakes. What got me thinking about this was the group of the surefire brake. It doesn't offer horizontal gas ports like the m11, rather its more of a 360 degree much like the harrell's brake. What deviates is the gamma brake, but maybe the angled gas ports help to steady the barrel while the bullet is travelling through it.
Also the limbsaver through its rubber properties probably helps to dampen the vibrations at the end of the barrel (notice it kept a very close zero assuming you zeroed the tc compass without anything on).
Limbsaver combos with the other brakes would be really interesting to see! Thank you again for taking the time to create this content!
Really good video Johnny! You helped me alot for choosing a tuner for my future 6.5 sherman max build. Thanks!
Years ago I literally memorized the Browning catalog..several things I noticed...all Browning rifles in 30 caliber were 1-10 twist..except the 308 ..it was 1-12 twist..you can find out for yourself that almost all rifle manufacturers use 1-10 twist in all 30 calibers..Browning had one exception..its very heavy 308 sniper rifle with a bipod bolt action..it used a 1-12 twist and a BOSS..it was the only 308 barrel they put a boss on..I took it as the Browning and Winchester rifles in 308 were so accurate that a boss was not improving it..another thing I did years ago was I took the boss off and fired several groups..it went from same hole at 100 yards to 5" group..I have several 308 Browning autos and one bar 3006 with a boss..my custom 18" short trac Browning auto in 308 I use a Limbsaver x-ring..its outstanding.
I suggest you google “Purdy prescription” and have a read. If you understand that, you will understand why your groups usually get noticeably better with the can screwed on. It is the same reason a barrel tuner works. Mr. Purdy developed this theory with regard to subsonic rimfire shooting in mind. I’d need to read again myself to refresh my memory as to how this might need to be modified to apply to supersonic centerfire shooting. But with the rimfire stuff the idea is that a barrel is a tube closed at one end like a pipe in a pipe organ and it needs to be tuned so a node of a wave of the odd harmonics is at the crown. And the barrel tuner is set to lengthen the barrel beyond the crown by a certain amount in order to put one of the odd harmonic nodes at the crown. There is even a spreadsheet to make this calculation extremely simple. And the calculation has been confirmed by many different people around the world in relation to their trial and error tuner settings. Confirmation after confirmation that the calculated value was within a few clicks of their trial and error tuner position, and likely differed simply because of measurement error for the calculation method. It even shows how to apply the method to tuning the barrel without a tuner attachment by instead counterboring the muzzle so the crown is down inside the barrel by the calculated amount. It is an incredible idea and more than worth your time to investigate. Weight is not involved at all. Only sound waves and harmonics inside a tube that is closed at one end.
Before highly tunable PCP airguns became popular, Field Target airgun shooters used air-strippers on their barrels to redirect the air pressure turbulence from disrupting the stability of the pellet as it exited the barrel. Later, as airguns became more tunable, with adjustable regulators and adjustable hammers, shooters were able to tune their guns so there was little or no excessive high pressure air following the pellet out of the barrel. I think it is possible your suppressor is acting as a closed air stripper.
As i posted on Kirk Boswell comment down the answers… "As we play with .01-.03 etc with out powder grains some of the devices you have used are compatible with those lines, the limbs aver, the thing with little holes and "dial nut" and the ones in the same line are just like our powder measure, you can play with them a bit more or less till you fine tune for your barrel harmonics/whipping. #johnny
sreloadingbench don't give up or consider yourself "confused" we all deal with things we don't know yet and learn sometimes take time and experience. I do LOVE your work, has been hard to hang around for a whole week waiting for your videos, it is TORTURE! LOL! Don't ignore the "muzzle breaks" but they are devices to tame the recoil even though they will tune your harmonics if in a weight close to the optimum barrel whip. God bless my friend, till best time... I really hope not long... Thank you again for the great work."
I'd love to see you play a snippet from the POTUS song Lump every time you bring out the lump.
The end mass is absorbing the frequency energy. the limb safer is also absorbing energy by transfer of energy mostly the same. I use the limb saver on my 22lr target rifles.
The bullet is leaving muzzle in less turbulent air with the suppressor on. Watch high speed footage of bullets leaving muzzles and you will see that gas actually exits before the bullet does causing the variations you are seeing. Putting a suppressor on slows the gasses down and allows the bullet to exit before the gas.
You are on the right track but misunderstand whats occurring. The propellant gases are travelling much faster than the bullet they are pushing. As soon as the bullet leaves the muzzle, those gases accelerate past the bullet and give it a kick in the ass. This is why a concentric and good condition crown is so important to accuracy. A damaged crown causes uneven gas flow out of the muzzle which gives the bullet an uneven kick in the butt. That causes the bullet to yaw, which causes a loss of accuracy.
A suppressor is a very efficient way of stripping the high velocity propellant away from the bullet and reducing the kick and resulting yaw the bullet undergoes. All of which results in increased accuracy.
Overall weights vs center of gravity position relative to the end of the barrel. The research I saw from the UK involved movement of a millimeter at a time.
Man, this hobby can definitely be frustrating! Can't wait for part 2. Keep your head up and keep the testing going. The more data we get, the better we can move toward a reasonable solution.
Powder charge changes barrel harmonic. I run a Ryan Peirce muzzle break I was running 42.2 grains of h4350 before the break. After I added the break my groups got worse. I am now running 40.9 grains of the same powder and am shooting .30 groups at 200 yards. Good luck
The answer to your last question is that all of them give the barrel different barrel harmonics. Playing with that adjustable one will make you a happy camper. Harmonics have to be adjusted in small incraments.
In several of my precision rifles I have gone through several muzzle devices to see what shoots best. My loads never changed but the difference between different brakes is apparent. If it shoots well let it fly.
😂😂😂😂 its time for a break lmfao no pun intended. After the flash hider that did outstanding
Love this channel. Best thing to watch when staring at the bench and contemplating loads/setup/etc.
I put one of the limbsavers inside the 15" handguard on a 16" Wilson barrel 358win with a target crown and it shoots amazing
To show what is possible with harmonic tuning, cut the number of variables to one. Small changes, on the order of a millimeter, on the Harrell’s brake would be fascinating to see. For the Limbsaver, 1/16” at a time. Testing the limbsaver with another device is too many variables! The Funshoot video armorer was getting results with one hour (clock face) of rotation with different shim thicknesses on an A1 flash device. Those are small steps, just like charge weights. Great video series..thank you!
My best educated guess is this:
I just started learning about barrel harmonics and my brain is working over time. I play guitar. I record guitar. I just watched another video about barrel harmonics and I learned two things: There is a frequency that happens in the barrel, and the bullet leaves the barrel before we see any motion in the barrel when a round goes off. Hang with me here because I have to explain myself before getting to the goods. Just like in another video, I'm going to use the guitar as an example because I actually do play guitar and I've taken 2 years of music theory and 4 years of choir, just don't make me sing cause that's why I play guitar. From music theory, I learned about a word called timbre, pronounced tam-ber: the character or quality of a musical sound or voice as distinct from its pitch and intensity. What this means is literally everything that can produce a vibration is a form of timbre. If you take a pencil and tap it on a desk, that noise you hear is a distinct pitch and intensity "timbre". Alright so why is this important? Well, when your rifle goes bang, there is an incredible amount of distinct pitch and incredible intensity forming a crazy high vibration. Your barrel would be like the desk in my example with the cartridge being the pencil, thus creating a freak-timbre-of-nature. Here's the thing, if the bullet leaves the barrel before this vibration in the barrel goes off, then what happens? I believe this theory is wrong and here's why. The speed of sound, according to Google, in feet per second is 1,125fps in ideal conditions but I'm not going to get into specifics. 1,125fps is the speed of sound. Do you know how fast the speed of sound is........... through a solid? It's 19,685fps or 6,000meters per second!!!!!
Wanna know what's even more mind boggling?! According to my Hornady Reload Manual, a 140gn BTHP at 38 grains of IMR 4451 is 2500fps! That means you can multiply the speed of sound to Mach 2! Now we're looking at the speed of sound in the 40,000fps range in a solid material. Okay let's put away the math book and get back to it. There is no way your bullet is leaving before the vibration of this blast goes off. This is barrel harmonics. This is what's happening inside your barrel. Let's go back to the guitar for a second. You ever watch a guitar string in slow motion after it's been plucked? You can literally see the frequency at which it resonates. Your barrel does the same thing except the frequency is so fast that it's too fast for your barrel to mimick for it's size. If you look at a high E string on a guitar, not the low sounding one, you can hardly see it moving because the frequency is too fast, hence why it sounds higher in pitch. But when vibrations start to settle inside your barrel, that's when you notice the barrel flexing. It's because the frequency is slowing down, the pitch is getting lower. The reason the rubber Limb Saver worked is because it helps soak up these pre-vibrations prior to your bullet leaving, which in turn, leaves your bullet alone, giving you better groups. Can you imagine what would happen if you made a barrel with a checkerboard metal/rubber design?! I'm not sure how you could do it with the rubber being it's weakest link, but it could be insane.
Gosh I have so much more to say but I'll leave it at this. It's my best guess 🤷
Oh yeah, the other muzzle devices are changing because you're messing with the timbre. The frequency inside the barrel is changing. Okay, I'm sorry, I have to mention something. Going back to the guitar, if you played an open string, we'll say the low E string, it sounds low. If you cut the string in half from the nut to the bridge, you'll be exactly at the 12th fret which is half of the fretboard. This 12th fret is the octave, it's the same note one octave higher and the vibrations are sped up twice the speed. If you keep your finger on the 12th fret and cut the string in half again, you get the 24th fret and again, it's another E note. If you continue cutting this in half, you'll run into E notes to infinity.
Fun fact: If you know what pinch harmonics on a guitar is, you literally pinch the string with your finger and pick and you get an incredibly high note, all over the string near the picking hand. These are harmonics. Your barrel is similar to the entire length of the E string if we didn't put frets on your rifle. When you change out the muzzle devices, you're messing with the density and length of the barrel, timbre. You're messing with the frequencies inside the metal of the barrel. Now I'm not sure if this is true, but if the transient waveform is at its max peak, the crest, the highest the wave will go, right when your bullet is leaving, you're going to get poor groups. But see I'm not sure if that's even true because the frequency is so high that the waveform would probably vibrate several times at the very moment the bullet leaves. Not sure if I believe this. Something that I do believe in is the length of the barrel and the timbre phenomenon. I am 100% positive something else is happening but I can't explain it or else I really would write part 2 of this novel.
Use the Harrel Barrel Tuner again!
However, not always adjust a whole revolution, but always two tenths of revolution further per shot passage.
The shot group opens and pulls back together!
That repeats the further you adjust.
Cross posted from /r/JRB:
Okay finally got home from work and eagerly watched this video.
What I am thinking is the amount of turbulance would have been much less on the ones that shot well. The Lump didn't touch the airflow, the Harrell's seems like it evenly on 360 degrees, and the limbsaver obviously did not touch the gasses.
The hard brakes, like the M11 and the M4-72 seemed to open it up with the gasses being vented violently to the sides.
I think that smooth gas flow plus the weight seems to be the key, like the lump.
Now what about the suppressor? Maybe the gasses are just evenly dissapated inside..
Maybe?
I have prescribed to Chris Long, OBT, and using Quickloads to start my initial load development for several years now. Keep in mind that Chris conducted all of his test with no muzzle devices affixed to the barrel. From my understanding of the OBT Theory, it postulates that the BORE DIAMETER increases/decreases as the shock wave travels. So, in regards to a threaded muzzle device, the bore diameter will not change. However, the reflected wave will as it encounters the muzzle device. I am not sure of your intentions of shooting various powder weight charges. I think you should have held the powder weight CONSTANT. As you know, in science, keeping the variables down to ONE will help in finding answers! Your POI shift is due to NON-CONCENTRIC threads on your barrel. There is an error introduced when the suppressor is affixed to your muzzle. The groups tighten up, however, since the factory threads are not concentric with your rifle's bore, the POI occurs with the suppressor. Unless you let your pencil thin #1 contour factory barrel cool down, by the time you got to the 3rd 5-shot group, your test has now introduced a 2nd variable = your barrel's temperature = larger groups. The Harrel's tuner brake seemed inconclusive [maybe more testing is needed].
The limb saver does work .. I like to start at the stock and move it forward 1/2" .. Then you will find the sweet spot .. Turns factory loads to .50 groups in most cases
Wow what a great video two thumbs up. Just throwing it out there some of what you saw has to do with Barrel vibration harmonics, and each device's ability to absorb and reverberate harmonics. It has to do with the ability to cycle and recycle Shockwave length. I am also currently working and planning to build my own Barrel device it has to do with the ability to extract the vibration from the Barrel
You gained a new subscriber! Great video! 👏👏👏👏
I test is good I think. Understanding the answers are the question. Lets say to ring a bell. To stop the bell from ringing, touch it, where you touch it and with how much weight or force determines how fast it stops ringing. As with the thick barrel, the shock or sound wave is smaller so the distortion is smaller, kind like a snare drum or thin metal, you can almost see the vibration in the disk. If you bleed of that vibration like a suppressor, distortion is minimized. I like the idea of attaching a weighted object to the barrel and test that. Just my thoughts
Its a combination of the amount of weight and the location of where that weight is placed.
It's doesn't take much movement to make a difference. You will find that on most tuners you'll find a good spot within a turn.
Read the Rex stuff,VERY interesting. I feel I learned a bunch.
I like you tested a blast forward break on the rifle; I like em they are nicer to my ears.
On the Harrels and Limb Saver, follow the instructions on adjustment. Tune them to tightest group.
1) Notice you said without a muzzle device it groups up to 1.5in. All but 1 device was an improvement on that. Perhaps because any extra material absorbs some of the shock wave. 2) The ammunition needs to change to suit the brake and place the "accuracy node" at the tip of the barrel. Theoretically the most "accurate" brake for your rifle is the one that just happens to place that node at the crown or absorb so much harmonic shock wave with mass that movement is negligible. It's just theory to me but someone else may have tested it.
If you're thinking that weight makes the difference ask the guy who made the lump make you different lumps that match the weight of those other devices. I would have to think that the ports on those devices being of different sizes would effect your bullets pointof impact.
Reducing flinch from muzzle blast can certainly add accuracy. Good thing muzzle blast is friendly with me 👍🏼
From my feeble understanding, and from what I just saw.... I reason that The barrel is like a guitar string, you want it to vibrate “just right” and “play the correct note” for accuracy, the weight as well as the shape/design chambers in the brake/how far they are spaced/how thick the metal is etc could influence how it vibrates, heck, the physical length of the device and the overall length of the barrel with the device could be a major factor in how it vibrates. A longer string plays a lower note etc.
I think there are 2 things going on.
first the weight that can have influence on vibrations (where you put the weight also alters the tune, kinda like playing a guitar.
Secondly, how the bullet leaves the barrel is also influenced by how the gasses are coming out behind and around the bullet.
Take a look at something like a Walther match air rifle. The barrels are only about 2/3 the length of the barreljackets, that other 1/3 is used to stabilise the air as the pellet leaves the barrel.
Now add to that, that usealy cheaper made barrels prefer to have some tension on them (like something pulling them down)
and i think you have your answer.
Wow great experiment
Weight is important but you also need to take the overall length of the barrel and muzzle device into consideration when dealing with barrel harmonics because the waves travel back and forth down the length of the barrel. Any change in length changes the distance the waves have to travel and will affect the results even if the weight is kept the same.
This was a good video. I have thought about this rabbit hole of accuracy and I think the Shockwave Theory is one of the best theories out there. Without reading that article, I thought about what happens when a round deflagrates. It reminded me of my guitar. I think the same principles apply to guitar and guns. I was taught years ago that if you plucked a guitar string at the open position, this note has an octave at the 12th fret. The 12th fret is exactly half the distance of the open note. So say the nut to bridge is 25" long producing an E note (just Standard tuning) the octave to this note is 12.5", essentially cutting the string in half. If you split 12.5" in half again, you get another octave. I believe the same principle is happening with firearms and completely relates to the Shockwave Theory. Do you know what the word timbre means? It is a characteristic of sound. Hearing the difference between talking and knocking on a door is timbre. You could probably recognize this difference in a blindfold test. Firearms have timbre too and I think this is the disconnect that people don't know about. The deflagration of a round produces it's on timbre with a hyper frequency that is so fast that you can't hear it. I once concluded that this shockwave MUST bounce through a rifle before the bullet even exits. Guess what?! This is the same principle as a guitar string! Both are frequencys and both produce musical notes, albeit the gunshot is so fast that you can't hear the exact frequency and I still don't know how it's measured but the same concept applies, or at least I think it does. By changing the length of your barrel with a brake or a suppressor, you are changing the frequency. An analogy would be like pressing your finger on a different fret of a guitar. You produce a different note! But there's more to it than just the reciever and barrel and brake. Timbre is the difference. You must include everything that the frequency touches and that includes the stock, the scope, and even your finger. All of these have some sort of effect on the timbre of a gunshot and it's frequency respectively. You also must consider everything else like temperature, powder charge, burn rate, metals used for the bullet and brass and steel etc. It all plays a major factor in timbre or the frequency we cannot see. Something that gave me a lightbulb when recording guitar is that sound moves in a 3D space and I know we've all seen computer sound waves before but these are displayed as 2D which is misleading when we think about the shockwave in a barrel. I just want people to critically think about this. The biggest effect is manipulating that barrel (guitar string) and the relationship to that shockwave because I still think there is something we don't know about with that. And maybe the Shockwave Theory from that article is true? Maybe the steel does compress and contract over the bullet squeezing it and releasing it. It does make sense because waves occur in 3D space and steel is no exception. If I had billions of dollars to experiment, I would love to see what happens if I designed a barrel made of rubber and steel. Basically a barrel that has checkerboard steel/rubber to soak up that shockwave before it can even return back from the muzzle. It wouldn't be able to affect the bullet I think because the rubber would soak up the frequency/vibration but the steel would still be rigid enough to hold it altogether.
Yes... barrel vibrations are the key to good groups. That was pretty much proven on the Browning 'muzzle break' device they had for awhile.
The TC rifle has a pretty light barrel. Simple device like the Limbsaver might be it for that rifle.
I'm watching your finger on the trigger... seems like you have a lot of movement there. (?)
Trigger is jumping up 'a lot' on the finger once it fires. (?)
Along with so many factors too long to mention and not enough brain power to think of them all. Harmonics, tuning, dampening, Is there gas pressure dispersment? Evenly dispersing the gas so not to interrupt the bullet as it leaves the barrel. like the suppressor for instance. The weight is a point of impact factor for sure. Dampening or tuning has a great role as well, Gas dispersment might or should play a role. This obviously don't explain all the results you encountered but it adds to the confusion! ; ) Love the testing you do!
Agree
thats exactly right elvis, what you really need is the Harrell's design about a half inch from the end of the muzzle so the gas is expelled while the bullet is still in the barrel, the gases are going a lot faster than the bullet, and air pressure is impossible to control, geten rid of the pressure before the bullet leaves the barrel is a good thing! as far as harmonics the bigger the better, thats a lot pressure being released in a split second, its like a tsunami going down the barrel, TAOFLEDERMAUS has a good vid showing it; (slow motion full auto ak- looks like rubber) after seeing that vid kinda makes ya wonder how ya can even get one inch groups!
Awesome test even though we are confused ... going to watch the others
Excellent as usual !!!!
The rubber limb saver deal would be out of the question on a ar15 for me on a bolt action it would be ok . The heat you get from a ar15 putting a lot of rounds down rainge would melt the rubber . For a ar15 I was thinking design a ar15 hand guard with a solid rail milled into the bottom rail like the 3/16 x 3x16 drilled and tapped and have the holes for the screws set every say inch all along the bottom part of the hand guard . Then find what reload or factory loads the AR15 likes then start moving the set screw in the bottom of the hand guard up against the barrel until you find the sweet spot . That is just a idea my wife thinks I think too much by the way great video .
Great video mate I’m about to start playing with a limb saver myself
Very interesting results... Especially when you consider how inexpensive the Limb Saver is and how effective it is. As you mentioned earlier in the video, some people who may not have the experience or no how to load their own ammo, just might benefit from a simple devise like this...
Timing of harmonic of the barrel make all the difference. I use quick load and the timing chart for barrel length. I get all my rifles to shoot Half or better. I hated the idea of running thru a ton of components and barrel life just to get a load for the gun. So, I figure a way using those two programs to quickly get the proper Moa I want. It works. I save on components. It does not matter if the gun is stock or custom.
for me most surprising were effects from the limbsaver ring - by far lightest device yet created one of the most significant effects AND had least POI shift from POA (if at all). this is something to be said about the device. I wonder if larger limbsaver will produce even higher dampening effect on the barrel shock wave - that's what you should include in your next test.
also, from where we stand at the end of this vid we can safely conclude that weight and weight alone to the end of the barrel is NOT a solution to tighter groups. it's more likely a circumstantial side-effect of having extra weight disrupting and altering barrel shock sine wave. we should step away from 'weigh as a reason' point of view and focus more on how to dampen those vibrations. obviously some of the devices has shown that dampening can be achieved w/o adding too much weight and i feel like that's were answer or one of the answers might lie.
Basically, you want to shoot from a dead barrel, such as a cannon with a rifle bore. Then there will be little or no barrel harmonics to distort the trajectory of the bullet. Theoretically, the axis of the bore is true and stable and the bullet exits the muzzle at the neutral axis. That what you want your muzzle device to do.
To further mess with your mind...it occurs to me that the harmonics may not be a 2 dimensional wave, but rather a spiral induced by barrel twist. The harmonic will outrun the bullet to the end of the barrel.
It's accurately a figure 8 pattern from a perspective close to in-line with the barrel, not the side perspetive.
You can see it in slow motion footage and is very dramatic on long barrels shooting large calibers.
The heavy barrels will also have a large effect in controlling consistent temperatures due to the higher thermal mass absorbing the heat. The grain structure in the metal will also effect the thermal expansion of the barrel. For example the Benelli Cryo barrels, the pattern is much more uniform than with standard barrels I've used due to the Cryo "tempering" normalizing the grain structure.
Harrells at 0, 50, 100, 150 settings would be a great place to start and see if anything starts to make sense.
Hi, how much doe the sliding weights on the Harrells weigh?
depends where you place then on the Barrel. Take the limb saver and try different locations like with in 5mm movements. sink it to the harmonics of the barrel.
Very cool experiment, My opinion for what it is worth is adding weight to the end of the barrel is just another variable being thrown into the accuracy mix. It may improve your accuracy and yet destroy your load harmonic. In other words your weight needs to be tuned for the load your shooting. As stated above its another variable.
the silecerco had a 0.585 group. but also look at the the independent prongs extending forward on it, they are like tuning forks.. they are going to vibrate at their own frequency. You would have to trim or extend the prongs to cancel out the harmonics. 3 prongs are going to somehow cancel each other out , but 4 prongs at a slighlty different length will also vibrate at a different frequency and cancel out harmonics. maybe someone can build a hybrid harrells and silencero tuner, have to not only cancel out the vertical but also the horizontal harmonics.
Just like that harrels, you need to adjust it in a little at a time, to see where the lowest harmonics are. maybe the harmonics are farther out and the dial need s to be extended longer , who knows. maybe try the silencero with the limbsaver or the harrels with limbsaver. limbsaver is going to absorb some vibrations, the balancers are going to neutralize the harmonics. what you need is a way to measure the harmonic frequency. and a way to neutralize it. tuning fork experiment.
Its like tuning a frequency specific radio antenna. if the antennas is too long or short you dont have an efficient antenna. It even could come down to Barrel length and a harmonic balancer tuned to it I would test the harmonics of the barrel first and see what frequency it vibrates at. shorter barrel higher freq, longer barrel, lower freq. As a comparison, use the 29 inch mosin nagant to test its frequency. even the number of thread on the barrel are going to change the harmonic frequency
heck you may find that even changing to a different bullet weight is going to change your harmonics, or even changing the powder charge by 0.1 grain. up or down. Now in the beginning you have 41.1 to 41.6 grains of powder getting the best result. well try narrowing the charge down 5 shot groups between 41.1 41.6 by 0.1 the tightest group may be at 41.3 or 41.4 grains. test with no attachments. get a base line control group.
1. fine tune the ammo as close as possible to the 0.1 grain.
2. fine tune the adjustable harrells . 0.885 may be the lowest value. I think you are going to need a longer harrells as the silencero is longer( the prong length) and yet has a lower group value.of 0.585
Excellent video, can't wait to watch the series. Keep in mind that some of the little guys might accidentally produce a favorable, accurate node alignment, in fact, big ones might also, so there might not be a clear set of rules forthcoming. The truth might hurt.