Time for me to call it a night. Keep it up!
Barrel tuners. Good or a waste of time?
- Thread starter geordiesniper
- Start date
Agreed again.
You earlier said "Ultimately, tuners time bullet exit with optimal muzzle position and is basically pretty easy to understand all we really need to know. PC is a different animal altogether."
PC is not a different animal as it makes bullets leave at the right place. That's positive, in my mind.
Perhaps my mind was not positively compensating when I did that.
I don't think you can move a node (point in barrel that does not vibrate at some frequency) to the muzzle in the range that compensates for muzzle velocity. That node will always be back a ways from the muzzle.
Al Harral's pages on vibrations show 8 different frequency bands whose nodes are not all at the same place shown in this link:
https://www.varmintal.com/amode.htm
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I just think they are two separate things that a tuner has some affect on...but so does a stock, for example. We agree...Just a lot more to figuring out all about pc than tuners, IMO.
Ok...now we might disagree but it's too late for me. Haven't had supper yet. There is NO place the barrel doesn't vibrate. Yes, there is top and bottom but of what? It's not just on a straight vertical plane. The muzzle never technically stops but top and bottom are the best places to have bullet exit happen. Good night!
Agree totally.
It the last few inches of the barrel forward of its node back from the muzzle whose vibrations mostly effect departure angle. Other barrel sections' vibrations don't matter much as shown in Al Harral's pages
https://www.varmintal.com/amode.htm
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dmoran
Donovan Moran
Here are 5 aspects that have proved factual to my own use of barrel tuners:
1. At 450yds & 1000yds (the two distances I do must all my testing and development at) it takes two separate tuner settings for optimal accuracy.
2. To get more "raw accuracy" from a barrel w/tuner, the load has to be re-tuned. Hence, a tuner is limited - IME.
3. My optimal tuner settings remain the same (or very near the same) ever time I've successfully re-tuned a load and gained more accuracy.
4. Tuner-brakes can adversely hinder accuracy on there worse settings, and do not optimize accuracy as well as does a tuner - IME.
5. The Mike Ezell PDT tuner has worked the most effective for me to date.
Personally could care less in the theorems of tuners.
What matters to me is what proves out on the targets.
1. At 450yds & 1000yds (the two distances I do must all my testing and development at) it takes two separate tuner settings for optimal accuracy.
2. To get more "raw accuracy" from a barrel w/tuner, the load has to be re-tuned. Hence, a tuner is limited - IME.
3. My optimal tuner settings remain the same (or very near the same) ever time I've successfully re-tuned a load and gained more accuracy.
4. Tuner-brakes can adversely hinder accuracy on there worse settings, and do not optimize accuracy as well as does a tuner - IME.
5. The Mike Ezell PDT tuner has worked the most effective for me to date.
Personally could care less in the theorems of tuners.
What matters to me is what proves out on the targets.
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jimmymac
Jim McGregor
Amen to that! This thread has drifted away from a how to into a this is why discussion.
When I first learned to drive, my dad told me that if I pressed the brake pedal real hard the car would stop fast and if I gave it a light touch it would slow down gradually. That proved true and still works perfectly to this day. Dare say, I’m an expert at using brakes without ever having to know why they work. I’m not saying I don’t have an understanding of why, but I don’t need to be so far in the weeds that I’m evaluating the composition of brake pads under a microscope.
I’m still waiting on Bart.
When I first learned to drive, my dad told me that if I pressed the brake pedal real hard the car would stop fast and if I gave it a light touch it would slow down gradually. That proved true and still works perfectly to this day. Dare say, I’m an expert at using brakes without ever having to know why they work. I’m not saying I don’t have an understanding of why, but I don’t need to be so far in the weeds that I’m evaluating the composition of brake pads under a microscope.
I’m still waiting on Bart.
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When I asked the general question as the OP, I was not expecting the detail of the why, how etc of tuners. But I am very grateful to Mike and Bart B for their very indepth responses and to give their time to explain to one and all from their perspectives.
It has given me more to think about using my tuner and in a good way. So thanks gents it is much appreciated!
Like anything else in life and shooting, there is always more to learn. Keep it coming!
It has given me more to think about using my tuner and in a good way. So thanks gents it is much appreciated!
Like anything else in life and shooting, there is always more to learn. Keep it coming!
Hey Les, don't go asking any difficult questions! (Like how to stop a certain 10 year old Northumberland Girl Guide beating us - especially me - in Heavy Gun matches!)
Mulligan
Silver $$ Contributor
Hi Laurie, the simple answer is make the young lady carry the heavy gun to the benches herself instead of her father lol. That will put paid to us being beaten every now and then. Going to Diggle this Sunday for the 600yd precision shoot so will meet my nemesis once more. Might fiddle with my tuner!!!
Anything that touches or is part of a gun has effect on tuning .
I feel the biggest factor is gravity .
Working with tuner something that I feel that is totally over looked . Is the way others are tuning
Not one person Uses the tune they
see above or below the point of aim for a reference .
To tune something you must have everything working the same .
To me I see a gun like a one cylinders
Engine
You have a cylinder you have ignition source and a combustion chamber And you have a mass it mass move .
Now we must add one more problem
That is the vibration of movement of the mass
The mass to me is mostly effected by gravity
So we should see a dwell time of movement at the bottom and the top
But to see that we must use a point of aim .
I have learned to see it
But I also have found when using a tuner
The movement that it takes to find it is almost impossible possible to move that little .
ALL tuners work
My belief is to make a gun shoot you must have low ES
You must do the same thing when shooting
And you must tune the movements
Of the barrels whet it has the longest dwell time in that location
Sorry for my bad wording
I feel the biggest factor is gravity .
Working with tuner something that I feel that is totally over looked . Is the way others are tuning
Not one person Uses the tune they
see above or below the point of aim for a reference .
To tune something you must have everything working the same .
To me I see a gun like a one cylinders
Engine
You have a cylinder you have ignition source and a combustion chamber And you have a mass it mass move .
Now we must add one more problem
That is the vibration of movement of the mass
The mass to me is mostly effected by gravity
So we should see a dwell time of movement at the bottom and the top
But to see that we must use a point of aim .
I have learned to see it
But I also have found when using a tuner
The movement that it takes to find it is almost impossible possible to move that little .
ALL tuners work
My belief is to make a gun shoot you must have low ES
You must do the same thing when shooting
And you must tune the movements
Of the barrels whet it has the longest dwell time in that location
Sorry for my bad wording
ergonsdad
Precision RAS Tuners
After reading all these comments and questions, I thought I would add my view of tuning. There seems to be one point of agreement. Tuners will improve precision if used properly. Tuning will make groups smaller and larger. Tuning will only work if you can measure the change in group size i.e. if the rifle shoots them all into one hole the tuner will not improve the group. Tuning requires very small tuner changes between groups.
Why tuning? When a rifle is fired the barrel vibrates in four modes: stretching, swelling (OBT), twisting and bending. The sum of all these vibrations create the motion at the muzzle. It is this motion that affects precision. The more the motion the less the precision. To see this, shoot a 2-shot group and look at the bullet holes relative to your point of aim. Unless the rifle is well tuned, you will see both bullet holes at some angle from your point of aim and they will be some distance apart. If you adjust the tuner the location and distance between the holes will change. The goal of tuning is to make the distance between the holes disappear. The angle from point of aim is due to the torsional vibration and the distance between the holes is due to the bending vibration. After tuning, the POI can be moved with the scope.
Many know that there is a Harmonic Balancer is on the end of an engine to manage bad vibrations. A barrel tuner is just a tunable harmonic balancer for a rifle barrel, only dealing with much more complicated vibrations. Any engineer taking a vibration course is taught that three things are required to tune a vibration: mass, spring rate and damping. In an engine harmonic balancer the rubber ring has both spring rate and damping. The outer steel ring is the mass. In a similar fashion a barrel tuner has the center rigidly attached to the end of the barrel with the moveable tuning ring on the outside and in some cases, there is damping in-between the tuning ring and the rigid center. Moving the tuning ring changes the tune until a desired sweet spot or sweet spots are found. There are multiple sweets spots in any barrel. See the figure below.
The tread pitch on tuning rings can be anywhere from 14 TPI to 56TPI. That means that the tuning ring travel can be 0.00020” to 0.00005” per degree of rotation. RAS uses 56 TPI and a label with marks 0.050 apart. This means on a 0.980” diameter barrel the RAS tuning ring moves 5.8 degrees or 0.00029” per mark. Frequently the first sweet spot is within the first 3 marks (18degrees) or 0.0009” of travel. Additional sweet spots will be found by continuing to move the tuning ring in very small amounts. Frequently the best sweet spot is the first one. The sweet spot window is +/- ½ mark.
As can be seen in the tuning plot below there were multiple tuning points that were better than the baseline without a tuner but there was one tuning point better than the rest. Also note that the Tuning Ring had moved less than 0.001” before finding that sweet spot.
My point is, if the tuning ring is not moved in very small increments it will pass over many potentially good sweet spots.
Jim
Why tuning? When a rifle is fired the barrel vibrates in four modes: stretching, swelling (OBT), twisting and bending. The sum of all these vibrations create the motion at the muzzle. It is this motion that affects precision. The more the motion the less the precision. To see this, shoot a 2-shot group and look at the bullet holes relative to your point of aim. Unless the rifle is well tuned, you will see both bullet holes at some angle from your point of aim and they will be some distance apart. If you adjust the tuner the location and distance between the holes will change. The goal of tuning is to make the distance between the holes disappear. The angle from point of aim is due to the torsional vibration and the distance between the holes is due to the bending vibration. After tuning, the POI can be moved with the scope.
Many know that there is a Harmonic Balancer is on the end of an engine to manage bad vibrations. A barrel tuner is just a tunable harmonic balancer for a rifle barrel, only dealing with much more complicated vibrations. Any engineer taking a vibration course is taught that three things are required to tune a vibration: mass, spring rate and damping. In an engine harmonic balancer the rubber ring has both spring rate and damping. The outer steel ring is the mass. In a similar fashion a barrel tuner has the center rigidly attached to the end of the barrel with the moveable tuning ring on the outside and in some cases, there is damping in-between the tuning ring and the rigid center. Moving the tuning ring changes the tune until a desired sweet spot or sweet spots are found. There are multiple sweets spots in any barrel. See the figure below.
The tread pitch on tuning rings can be anywhere from 14 TPI to 56TPI. That means that the tuning ring travel can be 0.00020” to 0.00005” per degree of rotation. RAS uses 56 TPI and a label with marks 0.050 apart. This means on a 0.980” diameter barrel the RAS tuning ring moves 5.8 degrees or 0.00029” per mark. Frequently the first sweet spot is within the first 3 marks (18degrees) or 0.0009” of travel. Additional sweet spots will be found by continuing to move the tuning ring in very small amounts. Frequently the best sweet spot is the first one. The sweet spot window is +/- ½ mark.
As can be seen in the tuning plot below there were multiple tuning points that were better than the baseline without a tuner but there was one tuning point better than the rest. Also note that the Tuning Ring had moved less than 0.001” before finding that sweet spot.
My point is, if the tuning ring is not moved in very small increments it will pass over many potentially good sweet spots.
Jim
WyleWD
Silver $$ Contributor
Mike, This has been a very informative thread, I do have a question (and probably a bit random) but do you see any difference between a heat stress relieved, cryogenically frozen, (or both) barrel(s) in relationship to how much adjusting the tuner might make in comparison to a barrel that has had neither? Just curious.
WDtypically about 1 mark with my tuner, from 100 to 1000. I can shoot to right at 570 from my shop but have to go to another place on my farm for 1000, so most of my testing is between 100 and about 570. From what I cansee, it's slightly less than a full mark for thatdifference and I believe right at a full mark at1000. quote from Mike on page 8
I don't think any barrel's muzzle axis angle ever stops; or dwells at some angle for any time.
It's constantly moving up and down for the most part; very little left and right.
The angle has to change to compensate for different muzzle velocities so slower ones leave at a higher angle.
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