Rimfire Muzzle Tuner Device? Worth it?

[OkayShooter]

Jerry, it's a good thing you can smile.

What's not good is when you recommend to shooters new to tuners that they ought to begin tuner testing at 200 yards. That's not only bad advice, it's dumb.

I see tones of tuners on PRS guns, so they gotta do something. You shoot a totally different sport, with totally different gun. So tuners on a heavy BR, cradled in rests might be less effective than on a lighter PRS rifle.

What's dumb about testing at the range you be shooting at? You 2 fight like married couple, BR vs PRS, 2 sports, 2 different setup for rifles, 2 different results.

 

[old303]

You can do lots of training and ammo development at a shorter distance and see what looks good and what doesn't, and if you can get out to the shorter range more often than you have access to the long range then don't waste either, but ultimately if long-range accuracy matters to you, you have to confirm it all works when you get all the way out there.

 

[Mysticprecision]

I see tones of tuners on PRS guns, so they gotta do something. You shoot a totally different sport, with totally different gun. So tuners on a heavy BR, cradled in rests might be less effective than on a lighter PRS rifle.

What's dumb about testing at the range you be shooting at? You 2 fight like married couple, BR vs PRS, 2 sports, 2 different setup for rifles, 2 different results.

Tuners, or a hunk of metal hanging off the muzzle, has always had an affect on a barrel. It is made overly complicated because the device is deemed to have qualities it most certainly does not. The confusion really stems from the assumption that the ammo is good and the tuner is hard/complicated. Just the opposite.

Factory ammo is rarely perfect and all we can do is change how the barrel vibrates in hope to get the two to "hook up".

It is also assumed that a Tuner made by someone must be made is such a way to be 'right'... not necessarily. Really depends on how heavy they are relative to the barrel applied. and how that combo shakes. Want to go down another rabbit hole... test using tuners that weigh differently... say an 8oz tuner vs a 16oz tuner.

Adding a weight has the potential to affect ALL barrels.... I am sure you will hear that adding a suppressor can make some rifles shoot really well. Same goes with adding a muzzle brake. What no one is discussing here is barrel harmonics... this is what the weight is trying to modify... no more, no less.

Short range, long range, it just doesn't matter... all you want to do is modify the vibration of the system so that quality ammo you can't control will work with a barrel to meet the desired task.

It is a forced marriage of sorts.

Simple

Jerry

PS for those willing to experiment, grab some wheel weights and hose clamps. I would want 6, 8 and 10oz combos to start. Strap them to the end of the barrel and see the affect vs naked. If one of the weights really helps to tighten up groups, that is the tuner weight you want for your application. I like the tuna can cause at 16oz, it affects pretty much any barrel... and also helps with forward balance. What you will see is that each weight has an affect on your groups... good or bad I do not know but if there is a change, then a tuner, weighing that much, can serve to help as a tuning aid.

simple

 

[Williwaw]

It is also assumed that a Tuner made by someone must be made is such a way to be 'right'... not necessarily. Really depends on how heavy they are relative to the barrel applied. and how that combo shakes. Want to go down another rabbit hole... test using tuners that weigh differently... say an 8oz tuner vs a 16oz tuner.

This is a seldom encountered idea that I have investigated. I wish I could credit the source and will do so in an edit if the name comes to me.

I have a weight set for my Harrell which gives me five different possible combinations. My question was what to go with. Starting at zero I shot one 5 shot group every revolution/25clicks. Using OnTarget I got mean radius and elevation for group center which produces two graphs. This can be repeated for each weight as indicated. It might be obvious there is likely nothing to be gained by doing all the weight options.

Not only did this one time test help me settle on a weight but also it pointed to most favorable ranges to work in. In my case very low and then in the 200's. In a way this is sort of like a Hopewell in this aspect.

Five shot groups are pretty minimal on their own but it was enough that the graph trends can be determined. Some may want to do ten shots. It sounds like a lot of ammo but my coming on three year old Vudoo has 85k rounds through it and I have complete confidence in my selected weight and tuner ranges. I do revisit the exact tune for every new lot.

Since I'm in this far I'll say a bit more. In the last four years or so I have shot almost 130k rounds in two rifles with tuners, equally split between Lapua and SK. There is no difference in terms of the difficulty to tune between the two brands. The difference, which is not a difficulty, is that more than likely, but not necessarily, I have to ignore or reshoot three or four more fliers per 100 rounds when testing SK.

Hope someone find this useful, I have dedicated a lot of time and resources and happily and willingly share my experience. If my results don't align with yours feel free to say so, maybe we can disagree respectfully and others will be more likely to engage in the discussion.

 

[Mysticprecision]

Williwaw, why I test at longer distances... at 100yds and beyond, changes are going to be very obvious to see. I have not used a 'tuner' (called weights for emphasis on what they are) lighter then 8oz but have added a muzzle brake of around 5oz to a 10/22 barrel and it dialed things in wonderfully. Yes, I got lucky but if it works...

Note, if you have a threaded barrel and don't want to spend the money on a tuner. Spin on hunks of steel of varying weights and see what happens. The weight tunes by moving on a thread or by changing its mass. For those with their thinking caps on, YES, you can move the weight on that barrel thread just like a conventional tuner and then lock it down once you find a desireable setting. This is not as elegant a system and does require some drilling and tapping but it can work. I have even seen shooters use large lock collars to add weight to the muzzle and then move them (I tried but not precise and a pita to work with)

From the numerous rifles and "weights" I have tested, the harmonic cycle seems to repeat within 1 1/2 revolutions... some as little as 3/4 rev (pretty sure all are on 24 thread counts???). With a lighter weight, I would expect more travel needed down the threads for the same effect. I would also expect you can go too light of a weight vs a thick barrel and see little to no change at all.

Shooters read TUNER and believe this part actually has some mechanical properties beyond just being a hunk of weight on a thread.

Looked at the Tuna Can and it has 10 numbers evenly spaced with a hash mark in between. Each number is 36 degs with the hash mark at another 18deg interval. I think this is a good spacing on a 24 thread count to get the weight moving enough to see some change. Maybe because the TC is so heavy, I see changes within a few numbers. When I am in the area showing positive results, each line (18deg) can change things in and out of the node.... a bit of back and forth and then settle on the 'close enough' setting.

You always have to discount those flyers .... why I suggest 'close enough'...

Jerry

 

[grauhanen]

I see tones of tuners on PRS guns, so they gotta do something. You shoot a totally different sport, with totally different gun. So tuners on a heavy BR, cradled in rests might be less effective than on a lighter PRS rifle.

What's dumb about testing at the range you be shooting at?

Simply because you see many guys doing the same thing doesn't necessarily prove anything. It also doesn't prove that in the case of a lot of guys are using tuners that the tuners are doing what they ought to do.

Many PRS rifles have shorter barrels than BR rifles. Shorter barrels are typically less responsive to tuners. In addition, rifles that are shooting in relatively identical circumstances such as from a front rest are more likely to allow a tuner to repeat it's good work than a rifle shot from changing circumstances.

My gripe with Jerry is that he is recommending to shooters that they should begin their tuner testing at longer distances such as 200 yards. Shooters new to tuners should understand why this is bad advice.

In any case, there seems nothing more to say. If shooters wish to begin tuner testing at 200 or 300 yards, I wish them good luck.

 

[Williwaw]

I

What's dumb about testing at the range you be shooting at?

IMO nothing. Jerry has said a bit about hanging a weight on the end of a barrel and somewhat demystifying (that was fun) what a tuner is. I would like to possibly fine tune the definition. It isn't just a weight but a weight at a specific position that changes the moment of the barrel. Moment is the product of mass and distance/length. When I'm shooting and tuning for 50 yards I shoot a series of groups moving the tuner 2 clicks which is 0.002 inches. My experience is the same as Jerry's in that I can usually find a tune within 1 1/2 revolutions. My measure of a good tune is one that tightens up my overall group as measured by the mean radius. I also consider the elevation of the group center. There is much more statistical significance to these metrics compared to using group size alone. I will exclude or reshoot obvious flyers.

Dr. Kolbe concluded that the maximum rate of barrel rise he documented with his instrumented barrel was just sufficient to achieve positive compensation at 50 yards. There has not been a lot of work done in this area (at least made public) but I have not seen any evidence to the contrary in my shooting. That would be the capacity for my rifle/tuner system to over compensate at 50 yards.

So what can be said of the 100 and 200 yard tuner working, I believe, beyond the effective range of PC. In the first place, they have the potential benefit of all the PC that can be wrung out of the system. And they have an adjustable inertial system to find more or less stable zones of barrel oscillation. Let us back up a bit and think about a weighted barrel vs unweighted or, said another way, a high inertia barrel vs a lower inertia barrel. Note also that the weighted barrel is pre-stressed downward. IMO typical barrel movement is a circular whipping motion with larger vertical excursions than horizontal ... ovoid more than circular actually. If the barrel is pre-stressed into a lower position the oval would have the same or less width but greater vertical. Longer distance shooters bread and butter is dealing with elevation so they may be able to tighten their groups by exploiting tuners in a different dimension than the 50 yards shooter.

Again OkayShooter, I would surely test at the range I was shooting at and would never presume that there was nothing to be learned by doing so.

 

[Mysticprecision]

Ah, now we are getting to the interesting bits and parts that rimfire shooters may not even know exists. Alot of research in the Centerfire world revolves around barrel harmonics. If you want to shoot itty bitty groups way down range, you better understand and tune for any issues.

Everything that I have learnt in the centerfire world, I have just applied to the rather simple world of rimfire. I say simple not because it is... but because there is so little we can do about it.

All the issues rimfire shooters see on target, centerfire reloaders have seen, diagnosed, and often, dealt with over the many many years. If you never leave the rimfire world and more restrictive, 50yd world, you may never know or care any of this exists.

for me, it was a quick and easy diagnoses several years back when I started rimfire PRS (we haven't even gotten into twists yet). I just applied common centerfire knowledge to the problem and it all made sense. You start with understanding that the ammo likely sucks and often, sucks badly.... have the awareness of other issues like harmonics and ballistics and rimfire is a simple problem to understand.

It is just a problem that has no real solution... except when you get real lucky and find some ammo made to above mediocre standards.

I know for a few rimfire die hards, this will seem like arrogance and overly simplistic thought... but it is based on a wide and comprehensive understanding of what happens when primers ignite.

There is nothing new wrt rimfire... if you want new horizons, compressed air is VERY intriguing.

Jerry

 

[250-25X]

Just to keep the conversation going: I loved watching the 3 positions finals in Paris (It lasts three hours but it's really very interesting )

I personally have been using tuners for over 25 years (on my prone and BR rifles) but I thought you might be interested to know that in the women's event, there were only two shooters out of eight using a tuner (a Starik and a Uptagrafft). Same thing for men, just two out of eight with a tuner...

 

[OkayShooter]

I

IMO nothing. Jerry has said a bit about hanging a weight on the end of a barrel and somewhat demystifying (that was fun) what a tuner is. I would like to possibly fine tune the definition. It isn't just a weight but a weight at a specific position that changes the moment of the barrel. Moment is the product of mass and distance/length. When I'm shooting and tuning for 50 yards I shoot a series of groups moving the tuner 2 clicks which is 0.002 inches. My experience is the same as Jerry's in that I can usually find a tune within 1 1/2 revolutions. My measure of a good tune is one that tightens up my overall group as measured by the mean radius. I also consider the elevation of the group center. There is much more statistical significance to these metrics compared to using group size alone. I will exclude or reshoot obvious flyers.

Dr. Kolbe concluded that the maximum rate of barrel rise he documented with his instrumented barrel was just sufficient to achieve positive compensation at 50 yards. There has not been a lot of work done in this area (at least made public) but I have not seen any evidence to the contrary in my shooting. That would be the capacity for my rifle/tuner system to over compensate at 50 yards.

So what can be said of the 100 and 200 yard tuner working, I believe, beyond the effective range of PC. In the first place, they have the potential benefit of all the PC that can be wrung out of the system. And they have an adjustable inertial system to find more or less stable zones of barrel oscillation. Let us back up a bit and think about a weighted barrel vs unweighted or, said another way, a high inertia barrel vs a lower inertia barrel. Note also that the weighted barrel is pre-stressed downward. IMO typical barrel movement is a circular whipping motion with larger vertical excursions than horizontal ... ovoid more than circular actually. If the barrel is pre-stressed into a lower position the oval would have the same or less width but greater vertical. Longer distance shooters bread and butter is dealing with elevation so they may be able to tighten their groups by exploiting tuners in a different dimension than the 50 yards shooter.

Again OkayShooter, I would surely test at the range I was shooting at and would never presume that there was nothing to be learned by doing so.

FYI.. It was more direct to Glenn response to Jerry about bad advice to test at 200. But I agree, why wouldn't I do most of my testing at the range I shoot. Easier to spot the errors.

 

[old303]

Even in the centrefire world I'm running into people who don't believe accuracy nodes exist, but that comes directly out of the idea of barrel harmonics and finding a spot where it's not vibrating as fast and you get less vertical dispersion from the inevitable wee round-to-round variations.

And with a big round it's a bigger effect, while it's more subtle in rimfire.

 

[deadman]

Its refreshing to see different opinions on this.

In the end though, you all are arguing over a kids toy.

 

[Longstud]

Its refreshing to see different opinions on this.

In the end though, you all are arguing over a kids toy.

I sincerely hope you don’t consider any firearm a toy. That attitude has people in suits standing around a hole in the ground after sitting in a holy place !

 

[grauhanen]

I would surely test at the range I was shooting at and would never presume that there was nothing to be learned by doing so.

There's a difference between shooting a tuned rifle/barrel at longer distances and tuner testing at longer distances.

There's no reason why at longer distances anyone shouldn't shoot a rifle that has a tuner setting that's been reliably verified to show improvement.

The question of whether someone ought to begin testing at 200 or 300 yards to find a good tuner setting is an entirely different thing. Since results at longer distances are bound to have considerable variation between them, it will invariably be very difficult to determine which tuner setting is a good one and which is not -- even when improvements can be found within a couple of tuner revolutions.

 

[grauhanen]

Dr. Kolbe concluded that the maximum rate of barrel rise he documented with his instrumented barrel was just sufficient to achieve positive compensation at 50 yards. There has not been a lot of work done in this area (at least made public) but I have not seen any evidence to the contrary in my shooting. That would be the capacity for my rifle/tuner system to over compensate at 50 yards.

So what can be said of the 100 and 200 yard tuner working, I believe, beyond the effective range of PC. In the first place, they have the potential benefit of all the PC that can be wrung out of the system. And they have an adjustable inertial system to find more or less stable zones of barrel oscillation. Let us back up a bit and think about a weighted barrel vs unweighted or, said another way, a high inertia barrel vs a lower inertia barrel. Note also that the weighted barrel is pre-stressed downward. IMO typical barrel movement is a circular whipping motion with larger vertical excursions than horizontal ... ovoid more than circular actually. If the barrel is pre-stressed into a lower position the oval would have the same or less width but greater vertical. Longer distance shooters bread and butter is dealing with elevation so they may be able to tighten their groups by exploiting tuners in a different dimension than the 50 yards shooter.

This is an a thought provoking way to curate the explanations that have been offered elsewhere for how tuners work.

You suggest that positive compensation (PC) works only about to 50 yards.

At longer distances such as 100 and beyond, however, you say that PC no longer is effective, that PC won't work at distances beyond 50 yards.

(For readers unfamiliar with positive compensation it's an explanation that says tuners work to reduce vertical dispersion by modifying the launch angles of faster and slower rounds in a way that the rounds will have the same POI at a certain distance downrange. This is the basics of Geoffrey Kolbe's work and that of Varmint Al. See, for example, http://www.geoffrey-kolbe.com/articles/rimfire_accuracy/tuning_a_barrel.htm and https://www.varmintal.com/a22lr.htm#Two-Flats)
_______________________________________

With regard to PC at 50 yards, when RFBR shooters use carefully selected lots of match ammo they may gain very little from PC. (For the general reader, yes, BR shooters still lot test when using tuners.)

At 50 when ammo ES is under 25 fps and SD figures are very good at under 7 fps, there's little that is gained. A ballistics calculator shows that vertical dispersion between two rounds that are 25 fps apart in MV should be no greater than 0.172". With good ammo it usually much less. The ballistics calculator shows that rounds only 10 fps apart in MV would have a vertical dispersion at 50 yards of 0.080".

In short, with the expected good ammo in use, vertical dispersion because of MV variation can be expected to be quite small. There's not much for tuner-induced PC to do.

Of course, this is not to say that tuners don't work to effect PC or that they don't help at 50 yards. They do, and they make enough of a difference that shooting RFBR without a tuner puts the shooter at a competitive disadvantage. RFBR shooters use tuners because rifles can shoot better with a properly set tuner than without.

It's not clear why PC won't work at longer distances. For reducing vertical dispersion alone, it seems that it is at distances of 100 yards and beyond that tuners could have a greater chance to shine.

At 100 yards, for example, the ballistics calculator shows that every 10 fps difference in MV results in about .25" of vertical dispersion. At 200 yards that same 10 fps difference in MV would cause about 1" of vertical dispersion.

Can you elaborate on what you believe it is that tuners do for a barrel at 100 and beyond that they don't do at 50?

 

[OkayShooter]

There's a difference between shooting a tuned rifle/barrel at longer distances and tuner testing at longer distances.

There's no reason why at longer distances anyone shouldn't shoot a rifle that has a tuner setting that's been reliably verified to show improvement.

The question of whether someone ought to begin testing at 200 or 300 yards to find a good tuner setting is an entirely different thing. Since results at longer distances are bound to have considerable variation between them, it will invariably be very difficult to determine which tuner setting is a good one and which is not -- even when improvements can be found within a couple of tuner revolutions.

You cannot test at 200 because too many variables. But to you. Can tell if a gun shoots better than another. Wthout using same ammo, in a ammo testing facility, in a fixture, no wind. Other than its a personal preference. When the variables are the same to be non conclusive.

 

[Williwaw]

Can you elaborate on what you believe it is that tuners do for a barrel at 100 and beyond that they don't do at 50?

Happily, the answer is nothing. It is just that what they do may be of more benefit to those shooting long range competition than 50 yd/m competitors. There are others in this thread who have much more experience than I do and are much better able to explain the advantages of long range tuner testing.

 

[grauhanen]

Happily, the answer is nothing. It is just that what they do may be of more benefit to those shooting long range competition than 50 yd/m competitors. There are others in this thread who have much more experience than I do and are much better able to explain the advantages of long range tuner testing.

Nothing? Are you sure? It seems like you're trying to have your cake and eat it too.

You say that tuners work by positive compensation (PC) at 50 yards. You also say that at 100 yards and beyond PC doesn't explain what tuners do.
To put it another way, you say that PC works to 50 but not at 100 and further out.

Let's take for granted that tuners do something good at longer ranges. If it's not positive compensation at 100 and beyond, what do they do to improve results at longer ranges?
__________________________________

Perhaps Bill Calfee's much maligned theory of the "stopped muzzle" (Calfee's term) is an explanation that deserves reconsideration. When Kolbe and the explanation of PC was promulgated, Calfee, a renowned rimfire gunsmith, rejected them. He was ridiculed for that. Unfortunately, both Calfee and his many detractors created a cloud of confusion about a lot of things, including his ideas about tuners. Nevertheless, they may help explain things about how tuners work at both shorter and longer distances.

Briefly, Calfee maintained that the tuner didn't work by achieving positive compensation. Rather the tuner "stopped" the muzzle, in effect fixing it so it didn't move because of harmonics. The result was the muzzle didn't move or alter the launch angle of faster or slower bullets as they left the barrel. Instead once a tuner setting established a "stopped muzzle" bullets left the muzzle at the same launch angle each and every time.

This would mean that vertical dispersion was only the result of MV variation between rounds. They would not be affected by any differences in launch angles caused by oscillations that would occur in an untuned barrel.

With a tuned barrel that has a "stopped muzzle" all distances can be shot with equal effectiveness at all distances, save for those caused by MV variation and the other factors that come more and more into play with increasing distance.

Of course this doesn't mean that a carefully verified tuner setting isn't required for tuners to do their job. A tuner that doesn't establish a "stopped muzzle" can't do it's job. Whether tuner settings are best established at shorter distances rather than longer ones seems to invite an obvious answer.

 

[Williwaw]

mmm cake. Whatever dude.

In regards to Calfee and his postulated stopped muzzle I have to say a bad theory is better than no theory at all. I got that from Mr. McGuire in grade ten physics. If I'm trying to figure out how something works rather than just making observations I prefer to be looking at those observations through the lens of a theory. Does the data support the theory or do I need a new theory. In my shooting career I have had to figure out all sorts of things and I always try to have a theory.

Back to Calfee. It seems an acolyte of Calfee would believe that our barrels oscillate up and down and that a weight at the muzzle can be manipulated to alter that movement predictively. That is a theory that lead me to a better theory. Why not time barrel exit to a rise rather than a stopped (or nearly stopped because it would never actually stop)position. That way slower, later arriving rounds would be launched at a higher angle possibly compensating for their greater drop when compared to faster rounds. PC and stopped muzzles share a common understanding of the physics, the difference is just how that knowledge is exploited. Seeing people who take sides on this one is pretty funny since both sides agree as to what barrels and tuners do.

While we are on the subject of tuners and tuning theories I hope to find the time to share my latest theory on the Purdy Rx. I'll be interested as to what others think and what their experiences have been.

 

[deadman]

I sincerely hope you don’t consider any firearm a toy. That attitude has people in suits standing around a hole in the ground after sitting in a holy place !

I do actually. They are all toys to me from a .22 rifle to a pistol to a centerfire rifle. I don't rely on a gun to live. Its a hobby. Doesn't mean I don't take gun safety seriously.