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Harrells Tuner/Brake or...?

PatMiles

Silver $$ Contributor
I'm looking at adding a tuner/muzzle brake to my 6.5 CM RPR.
Can I get some real world feedback?
TIA
 
I am interested in these as well. Been looking at them off and on but haven't pulled the trigger yet. Hopefully someone with first hand experience can let us know something...
 
I’ve used tuners extensively. They work. That the tuner has vents in it is irrelevant to tuning.

Ok. Muzzle brakes. I’d check the rules carefully to make sure that brakes are allowed in the formats that you play.

Also, in another thread, someone mentioned the value of tuners to those that do not handload. FWIW, I think that it is likely that a tuner would help. But, I don’t think that anyone is going to get the most out of a chamber/barrel without handloading.
 
Greg,
Thanks for the reply.
I don't shoot any games so holes in the tuner is a non-issue. I've also read extensively regarding the effectiveness of tuners but have never read about the effectiveness of a tuner/brake thus the inquiry. As a reloader, it is apparent that finding the load the gun likes and then dialing in the tuner is the path to wander down.
Anybody else?
 
Ok. Some more on this.

A tuner will not make a bad barrel good. Nor the reverse.

It will not make a crappy load good nor the reverse.

Let me start by saying that the the barrel oscillates like a tuning fork when you shoot. For the sake of this discussion, let’s be simplistic and say that the barrel whips up and down to form the halves of a sine wave at the top and bottom.

Now, where the muzzle is pointing when the bullet leaves it is where that bullet is going.

That’s important because there are *always* small variations from average in when the bullet gets to the muzzle. At a given moment of shooting, those variations are small, but significant to some shooting formats.

Across a shooting day, as the temperature increases, the velocity will increase and change the average from which those small variations occurs.

That’s important because on one half of that sine wave, the oscillation aggravates the small variations, while on the other half, the oscillation actually helps compensate for the small variations. This is called “positive compensation”.

When a short range benchrest shooter changes powder charge to chase the tune during a shooting day, what he is doing is keeping the average on the correct side of the sine wave.

BTW, It is also why the shooters groups get tiny right before they blow up. :/.

You can see this by drawing a horizontal line across a 2’ wide target and vertical lines at even intervals on the line to form target crosshairs. Kinda like graph paper, if that helps. Then shoot two or three shot groups from left to right increasing powder charge in small increments, say 0.3 for small cartridges and 0.5 for big ones. You will see the group’s form a sine wave. Half above the horizontal and half below.

The “correct side” is the side where increasing powder charges move the groups *down* the page. The bad side is when the opposite happens.

What a tuner lets you do is stay on the correct side of the sine wave *without changing powder charge* (or seating depth, etc). It does this by tuning the barrel to the load rather than the normal method of tuning the load to the barrel.

There are other benefits to a tuner (and other downsides), but that is enough for now.

The way that I use a tuner is to find a load that works...that is in the middle of the “correct side” using the “graph paper” method that I described above, then use the tuner to stay there as the temperature increases during the match.

I think of it this way. It’s not what’s really happening, but it’s a way to remember. As the temperature increases, the velocity increases. I move the tuner toward the action, as though I were shortening the barrel to reduce the velocity.

I highly recommend that you get with “gunsandgunsmithing”’on here. That’s Mike Ezell. He has a metric buttload of tuner experience and manufactures a very nice tuner. He’ll explain this better than me and correct anything that I’ve gotten wrong.

That’s all I’ve got and my thumbs are about to fall off.

Greg J
 
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Greg,
Thanks for the reply.
I don't shoot any games so holes in the tuner is a non-issue. I've also read extensively regarding the effectiveness of tuners but have never read about the effectiveness of a tuner/brake thus the inquiry. As a reloader, it is apparent that finding the load the gun likes and then dialing in the tuner is the path to wander down.
Anybody else?

Any tuner or tuner/brake combo should allow you tune your barrel. With a tuner, there is no need to change your everyday load combination. You start your tuner process making very small adjustments by moving the tuner in and out. What I don’t like about the tuner/brake combination tuners is the holes in the brake portion allow build up of carbon which can add weight do to the carbon buildup. Brakes are also a PITA to clean. Is this a big deal? Probably not but why add any variable weight to a device you are only moving slightly when tweaking your tune? All my guns/barrels have their own Ezell Tuner.
Ben
 
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31AB08A8-9287-412A-990B-417523FBBEED.jpeg Here is a target where I used the tuner to move a known good load around to show a friend. You can really clearly see the wave on the right side of the target. The right side is at the top...
 
Ok. Some more on this.

A tuner will not make a bad barrel good. Nor the reverse.

It will not make a crappy load good nor the reverse.

Let me start by saying that the the barrel oscillates like a tuning fork when you shoot. For the sake of this discussion, let’s be simplistic and say that the barrel whips up and down to form the halves of a sine wave at the top and bottom.

Now, where the muzzle is pointing when the bullet leaves it is where that bullet is going.

That’s important because there are *always* small variations from average in when the bullet gets to the muzzle. At a given moment of shooting, those variations are small, but significant to some shooting formats.

Across a shooting day, as the temperature increases, the velocity will increase and change the average from which those small variations occurs.

That’s important because on one half of that sine wave, the oscillation aggravates the small variations, while on the other half, the oscillation actually helps compensate for the small variations. This is called “positive compensation”.

When a short range benchrest shooter changes powder charge to chase the tune during a shooting day, what he is doing is keeping the average on the correct side of the sine wave.

BTW, It is also why the shooters groups get tiny right before they blow up. :/.

You can see this by drawing a horizontal line across a 2’ wide target and vertical lines at even intervals on the line to form target crosshairs. Kinda like graph paper, if that helps. Then shoot two or three shot groups from left to right increasing powder charge in small increments, say 0.3 for small cartridges and 0.5 for big ones. You will see the group’s form a sine wave. Half above the horizontal and half below.

The “correct side” is the side where increasing powder charges move the groups *down* the page. The bad side is when the opposite happens.

What a tuner lets you do is stay on the correct side of the sine wave *without changing powder charge* (or seating depth, etc). It does this by tuning the barrel to the load rather than the normal method of tuning the load to the barrel.

There are other benefits to a tuner (and other downsides), but that is enough for now.

The way that I use a tuner is to find a load that works...that is in the middle of the “correct side” using the “graph paper” method that I described above, then use the tuner to stay there as the temperature increases during the match.

I think of it this way. It’s not what’s really happening, but it’s a way to remember. As the temperature increases, the velocity increases. I move the tuner toward the action, as though I were shortening the barrel to reduce the velocity.

I highly recommend that you get with “gunsandgunsmithing”’on here. That’s Mike Ezell. He has a metric buttload of tuner experience and manufactures a very nice tuner. He’ll explain this better than me and correct anything that I’ve gotten wrong.

That’s all I’ve got and my thumbs are about to fall off.

Greg J
Greg, very well said. You really got the idea across in what I think is a very understandable way... accurately.

Different tuners will yield slightly different results, for one reason or another, but they all work on the same principle. It's not really different than tuning with power charge and seating depth. It's just way easier with a tuner.

Good post!--Mike Ezell
 
View attachment 1031001 After a PM or two, here is some more explanation.

Caveat: I do short range. Not long range. Can’t speak to long range.

Also, while I have experienced this directly, I didn’t come up with it. I got onto this from talking with several HoF short range benchrest shooters.

You can see this “good part” really clearly on the top/far right of the previous picture that I posted. Immediately before that, you can see the bad side. (Now, truth in advertising: As I said in a that post, I was actually moving my tuner to show the effect to a friend, not increasing powder charge).

Why the upswing? Because bullets that get to the muzzle late, generally moving slower, are put onto a higher trajectory. Bullets that get there early, generally moving faster, are put onto a lower trajectory.

It’s not obvious, but speed that the barrel is oscillating at the point that you tune around...the average exit point...only allows the compensation to be right at one distance.

I’m kind of reaching here, but I think there is opportunity there for experimentation with respect to barrel profiles to allow for better compensation. View attachment 1031001
 
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GSPV:

I'm mulling over your chart. Some questions.

1) Is the y-axis depicting muzzle position relative to a static zero or the downrange point of impact of the bullet?
2) What is the x-axis denoting? Powder charge, bullet speed, or time?
3) What physical factors other than length do you believe influence barrel harmonics?

Thanks.
 
View attachment 1031001 After a PM or two, here is some more explanation.

Caveat: I do short range. Not long range. Can’t speak to long range.

Also, while I have experienced this directly, I didn’t come up with it. I got onto this from talking with several HoF short range benchrest shooters.

You can see this “good part” really clearly on the top/far right of the previous picture that I posted. Immediately before that, you can see the bad side. (Now, truth in advertising: As I said in a that post, I was actually moving my tuner to show the effect to a friend, not increasing powder charge).

Why the upswing? Because bullets that get to the muzzle late, generally moving slower, are put onto a higher trajectory. Bullets that get there early, generally moving faster, are put onto a lower trajectory.

It’s not obvious, but speed that the barrel is oscillating at the point that you tune around...the average exit point...only allows the compensation to be right at one distance.

I’m kind of reaching here, but I think there is opportunity there for experimentation with respect to barrel profiles to allow for better compensation. View attachment 1031001
Good explanation of "positive compensation" and what to look for, Greg. I agree about there being room for the right people to experiment with barrel contours in this regard as well. Putting a mass at the end of the barrel effectively does this, as do straight contour barrels.--Mike
 
6D90BCEE-FB18-460B-AE43-3E94183F89EC.jpeg More explanation on the quick and dirty chart. Sorry. Doodled it up while on a conference call. :O
 
Those sine wave charts can be a little misleading, as the barrel is mostly going up and down not actual in a sine wave. Also increasing powder charge has the effect of pushing the bullet out of the barrel quicker relative to the sine but it also changes the pressure wave and how the barrel may be vibrating. Deciphering a good spot on the sine wave that will work at longer distance would be great if we could learn to do it consistently. This is why so many of us in long range push "tuning at the distance you compete". If you shoot a 1k ladder it will show the sweet spot every time.

As far as adding mass goes, I dont think it is always the answer at least in LR. The rifles rotation on its center of gravity plays a role in PC. Adding muzzle weight slows this, as well as slows the vertical travel of the muzzle in its harmonic. So far in LR it looks like the faster we can get the muzzle going up, the better.
 
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GSPV:

I'm mulling over your chart. Some questions.

1) Is the y-axis depicting muzzle position relative to a static zero or the downrange point of impact of the bullet?
2) What is the x-axis denoting? Powder charge, bullet speed, or time?
3) What physical factors other than length do you believe influence barrel harmonics?

Thanks.

The chart should have more on it. Sorry. See updated picture of it.

1. The vertical axis depicts the center of the group relative to the point of aim.
2. The horizontal axis depicts increasing powder charge in small increments. Like 0.3 grains. This, like velocity, is a stand-in for bullet exit time, which is difficult for us to measure. Gotta make do with what we have.
3. Barrel profile. Whether there is a tuner or some other weight at the end of the barrel...which gets down to barrel profile. With that said, at the danger of getting too far into the weeds, it’s not just the barrel, it’s the whole system. One example is the stock.

Folks, I don’t want to come off as an expert about this stuff. I’m just a science enthusiast that tries to apply it to shooting.
 
Adding muzzle weight slows this, as well as slows the vertical travel of the muzzle in its harmonic. So far in LR it looks like the faster we can get the muzzle going up, the better.
I don’t think that that is necessarily just in long range, either. Longer distance would seem to require more vertical movement of the barrel with respect to the variations in exit time.

Way back when, when the tuner first came on the scene...in rimfire benchrest...one of the first things that happened was a move to longer, more cylindrical, barrels.
 
That could be one way of making tuners more effective at long range. Stock flexability to me has always been huge because of this. I have made some very flexible stocks and so far have not found where it starts to hurt. Center of gravity is big and we are on to barrel profiles now, and so far, so good there too. PC is the real deal and using it to build a rifle around IMO works.
 
Those sine wave charts can be a little misleading, as the barrel is mostly going up and down not actual in a sine wave. .

The charts are just the POI with respect to the POA. They aren’t trying to say anything about the mode of oscillation of the barrel (there are, what 7 modes?, some relevant, some not).

Just like in the first picture that I posted. I keep this simple. I draw a horizontal line on a pretty big target, like 24”, and draw vertical lines to make target crosshairs at even intervals, say every 3” all the way across it. I then shoot three shot groups at each crosshair. Each group’s powder charge goes up by a small amount. Say 0.3 grains.

You can get a bit fancy and use that software package to plot the center of the group. I have done that. But, I can usually just eyeball it.

Man, we are way down in the weeds for someone asking if a tuner works.
 

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