Tuner Guidance Please

Fred Bohl

Fred Bohl

Retired Engineer
Would those of you that believe your have been or are successful with tuners on center fire benchrest rifles please provide some guidance for me and others like me that have become confused by all the discussions to date. I am a retired engineer and have been shooting for over 55 years including some competitive benchrest shooting so I’m neither ignorant nor inexperienced.

I have lost track of what problem a tuner is supposed to be solving and how the tuner is used to solve the problem. To put the answers in terms I might be able to follow let us start with the assumption that I have a LV rig that I have found a combination of bullet, powder, load, and seating depth that will deliver (in normal conditions) groups of 0.15 to 0.25 MOA.

1. What characteristics of the groups would indicate that using a tuner could improve the performance of this rig?
2. If converted by installing a tuner, what improvements could be expected?
3. How would the tuner be used to achieve those improvements?

Understand that I’m not asking for a theoretical explanation of how the tuner works (that horse has been thoroughly beaten), but rather a user guide. More along the lines of: if you see X and Y; install a tuner then use it to do P, D, & Q; and success will be indicated by at least Z% reduction in X and Y.

For my fellow engineers that are familiar with the concept called design of experiment, I am asking for the existing users to:

1. Define the affected parameters.
2. Specify the procedure to be used.
3. Set the level of improvement that proves the hypothesis.
 
Fred, re. the tuner discussion, we ain't there yet. Everyone is still trying different approaches and theories.

Some background. In 2005 the NBRSA and IBS temporarily approved tuners. Then the IBS did not continue approval after the 2005 year until this year.
In the 2005 year the NBRSA tuner design parameters were much different than the IBS requirements so there was not a lot of interest in the centerfire community at that time.

Starting this year a centerfire shooter can use the same tuner design and that among some intermediate experimentation by folks like Gene Beggs, Ralph Stewart, Shelly Davidson, Jackie Schmidt and others have increased interest. A guy who goes by Varmint Al has added much to the FEA part of the discussion.
http://www.varmintal.com/
http://www.varmintal.com/atune.htm

So, grab a gun, install a tuner and join in.

As to your conceptual DOE parameters, we ain't that formal or accommodating.
 
Fred Bohl said:
For my fellow engineers that are familiar with the concept called design of experiment, I am asking for the existing users to:

1. Define the affected parameters.
2. Specify the procedure to be used.
3. Set the level of improvement that proves the hypothesis.
Click to expand...

Well, I'm no engeneer (BS MA Chem), but here is what I intend to do:

1. The affected parameter is group size. Measured center to center as would be measured in a match. I suspect, based upon past experience, that dispersion will not be in a purely vertical plane, but circularly with the diameter of the circle varying with the load (i.e., powder charge).

2. I intend to chamber a new .22 S&M barrel threaded to accept a barrel tuner at the muzzle. Then, I intend to establish a baseline load using conventional loading techniques, i.e., establish a seating depth and ultimately a powder load, that shoots the smallest diameter groups. Once this base line is established, I intend to vary the powder charge in either .05 or .10 gn increments (up and down) and record any changes in the baseline groups. This shooting will be done indoors at 100 yds with premeasured charges (using a milligram scale) so I do not expect atmospheric conditions to be a major factor although they will be recorded. If I can obtain a chronograph with IR screens, this data will also be recorded.

Next, I intend to screw the tuner on the muzzle and establish a baseline. I would initially start with the same optimized load as used without the tuner and vary the position of the weight to determine whether the initial diameter group size could be duplicated or exceeded by dialing the tuner only. If it could be dialed to meet or exceed (which BTW would be a significant accomplishment in and of itself) the original diameter group size of the tunerless barrel, I'd then begin varying groups by .05 to .1 gn and record the change in diameter of the group sizes. If at least equal diameter group sizes could not be achieved by dialing the tuner, I'd first try varying the powder charge and then the seating depth to see if a baseline equal to the original diameter could be established and then vary that new baseline in +/- .05 or .10 gn increments and record the change in group size and see what if any improvement in group size could be attained.

Arguably, a rail gun would be a better platform for this test, but the logistics of testing facility dictate the use of a bag gun as I've had better luck shooting a bag gun from the benches of this particular facility.

3. One barrel and one tuner really doesn't prove much. But if several people conduct similar experiments and obtain similar results, or if the experiment is repeated several times, perhaps we can determine whether a tuner "broadens the tuning range" as claimed by some proponents of the tuner.

I ordered a tuner today. Have not decided on a diameter barrel yet, so one has not been ordered -- I'll probably do that shortly. The rest -- stay tuned. Pun intended.
 
Fred

I was talking to a rather well known Benchrest Shooter a couple of weeks ago, and he talked me into building him a tuner. He said he wanted one of mine because I was one of a handful of shooters who actually wins with a tuner on the Rifle. He just wants to play with it some to see what is going on.
Here it is in simple terms. Most Rifles can be made to shoot up to it's potential with a tuner. In fact, unless there is something mechanically wrong with the Rifle Combination, I would say any Rifle that is mechanically sound can be made to shoot as well as it is capable with the addition of a tuner.
I have seen shooters with Brownings go from shooting 1 1/2 inch groups with a given ammunition to shooting 3/4 groups, simply by adjusting the BOSS System. That is about as good as it will get.
Of course, with a Rifle that is designed for extreme accuracy, such as a Benchrest Rifle, the gains are not near so great. But, say you have a really well put together Rifle in 223. It is not a Benchrest Rifle, but is capable of .350 groups and better.
Say you wanted to go on a Live Varmint Hunt, but did not wish to load up 500 rounds.
So, you go to a professional loader, or a Gun Show, and buy some bulk Ammo, suitable for your purpose.
But, The Rifle will only group 3/4 to 1 inch inch with it. By adding a tuner, you just might be able to take that same ammo, and cut the group size in half. That would be great. The 'dogs" would be in trouble.
I use my tuners to keep my Rifles in tune at Matches. I have found, (stumbled on), a Powder- bullet-barrel combination that shoots pretty good. I have found that this combination aggs at it's best potential when I shoot in at a higher than normal pressure curve. In the past I would change the charge, the seating depth, and the neck tension to keep the Rifle agging. Now, I leave all of this alone, and if I sense the Rifle is getting ragged, I will turn the tuner to get it right again. I find that life is much simplier this way. Others think it is all smoke and mirrors. All I can fall back on is my (sometimes) success in The Gulf Coast Region.
Mind you, it will not be shooting any better than if I would have played with the powder, neck tension, seating depth, or any thing else. But, with the tuner, I can make the decision right there on at the line, do the adjusment, and (hopefully), keep the Rifle agging at a competitive level.
The draw back is that I had to figure out a way to keep my Sporter, (LV), from not going over 10.5 pounds with the addition of the 6 ounce tuner. I did it my lightning the barrel, which seemed to have no downside at all.
That is the scoop from a Benchrest Shooter who actually uses a tuner in Competition, and on occasion, wins with it........jackie
 
Last edited:
Fred Bohl

Fred
1) If you have vertical in your groups.
2) It will remove the vertical
3) It allows you to eliminate the vertical.
On your second set.
1) It moves the barrels node to the muzzle
2) You use two widely spaced shots(velocity) to set it.
3) Your target
Lynn
 
Sorry 'bout that

Varmint Al said:
This page has a better description of the FEA analysis of Esten's Tuner. http://www.varmintal.com/aeste.htm#Ladder

Good Hunting... from Varmint Al
coyotel.gif
Click to expand...



In my post above I omitted Mr Esten's name and his important contribution. I apologize for this error.
 
Doe

Fred

My experiments will be based on DOE--I am very familiar with it and spent many years using it.

In fact I am working on an Ishakawa diagram for the tuners as well as for bullets.

Jackie's experimentation up this this point has been based on sound experimentation and he has determined that tuners are an aid.

Jim
 
Gentlemen,

First, thank you all for responding. Also thank you all for at least attempting to provide useful replies.

Varmint Al and Esten Spears,

I have been following your efforts to the best of my ability. Your hard work and generous contribution of your time and analysis has been an ongoing inspiration to my interest and understanding of the topic. My thanks for you’re sharing this effort with us all.

Mike Marcelli and Jim Borden,

I will be anxiously awaiting the reports on your results as you two seem to have the best grasp of a means to conduct a truly useful experiment. Particularly testing that has a prospect of helping to clear my confusion.

Jackie Schmidt,

Your “just go out and try it” attitude and common sense style of reporting results has been responsible for keeping this old engineer interested in the potential for tuners being “real world” useful devises. Many of the exchanges and threads on the theory of what tuners do and how they work have come very close to sounding like the pitches of snake oil salesmen and driving me away. But just at the right time you’ll throw in one of your quick comments on what you’ve done and a realistic account of what it appears to do. Then I keep reading.

FURTHER QUERY:

Since you all are or will be experimenting further I will assume you have some faith in the potential of tuners. Also, you’re common expectation appears to be reduction in group and/or aggregate size. Therefore I pose the following query:

Do you envision an eventual tuner design that would allow the user to fire three sighting shots and from the pattern observed and the predictable operation of the tuner then be able to make an adjustment to correct the observed pattern flaw for subsequent shots?
 
Fred

On you last question, that is exactly what I do at a match. Often, during the first 10 minute match, or the sight in period, if that is used, I will toss a quick three shot group on the sighter, looking for any verticle. If I am not satisfied,I will turn the tuner 1/4 or 1/2 turn, and shoot another three shot group. It rarely takes more than three groups to get the Rifle shooting flat. If I have plenty of time, I will go 1/8 turn one way or the other.
I have determined through my best guess that my tuner goesfromonenode to the next in no morethan 1 1/4 turn, so I try stay within that boundry.
Keep in mind,while you are doing this, the clock is running. You have to use a little common sense, and not get shookup. I have been using a tuner for for a while now, (over three years), and have sort of developed a feel for what I need to do. Sometimes, I end up about where I started, just figuring it's going to be one of those days.
During the agg, if I think the Rifle is getting ragged, I will repeat the proccess, if I am sure it is not me. (amagine that). That is a decision you have to make at the line. Turning the tuner when it was not out of tune is not a good thing.........jackie
 
In my opinio

jackie schmidt said:
On you last question, that is exactly what I do at a match. Often, during the first 10 minute match, or the sight in period, if that is used, I will toss a quick three shot group on the sighter, looking for any verticle. If I am not satisfied,I will turn the tuner 1/4 or 1/2 turn, and shoot another three shot group. It rarely takes more than three groups to get the Rifle shooting flat. If I have plenty of time, I will go 1/8 turn one way or the other.
I have determined through my best guess that my tuner goesfromonenode to the next in no morethan 1 1/4 turn, so I try stay within that boundry.
Keep in mind,while you are doing this, the clock is running. You have to use a little common sense, and not get shookup. I have been using a tuner for for a while now, (over three years), and have sort of developed a feel for what I need to do. Sometimes, I end up about where I started, just figuring it's going to be one of those days.
During the agg, if I think the Rifle is getting ragged, I will repeat the proccess, if I am sure it is not me. (amagine that). That is a decision you have to make at the line. Turning the tuner when it was not out of tune is not a good thing.........jackie
Click to expand...

What Jackie has said here is the oness will still be on the operator, to some degree unless the "Barrel Stopping" situation becomes a reality and then one can simply make sure they are pretty close with their loads and the "Stopping" characteristics of the Tuner-Barrel combination will forgive some things.

Going at it with either an adjustment using DA or some sort of ambient atmosphere measurement will leave a lot of know how still being requied by the shooter. Let's hope the Barrel Device will evolve to the "Stopping" characteristic. Some of us are getting too old to be able to remember much !
 
To all that have replied or read this thread,

I would seem that my query has poured salt in an open wound so I sincerely apologize for that outcome. I had intended to try to avoid the battle and move on to determining if tuners had potential to be worth my time and expense to join the experimenters. After this lesson I will leave tuners to the next generation - I'm too old and tired for making myself a target.

Thank you all who have chosen to experiment and to share your results with the precision shooting community.

In the future I'll avoid posting questions at all and also try to stay away from topics showing controversy.
 
Fred

I sure did not mean to sound controversial. I stated what I believe to be the truth. My tuners work, and are proven in Competition. I know ofknow other way to qualify something for which the main purpose is to be part of a Benchrest Rifle.
I don't plan on changing a thing for the upcoming season, which starts next week end for us in The Gulf Coast Region.
Ask away. You can't learn if you do not inquire.......jackie
 
Fred: No need to stop posting questions or soliciting opinons...in fact, just the opposite.

As I posted on another forum in response to this same question, the whole thing with 'muzzle devices' has many people just quietly working with them and forming their own opinions.

Good shootin'. :) -Al
 
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