HOW TO USE A TUNER, Part 5

G

Gene Beggs

Active member
Good morning everyone. This will be my fifth and final post in this series on the use of tuners. We have enjoyed some terrific feedback from many great minds and I deeply appreciate your joining in the discussion.

After reviewing part 1 thru 4, I believe we have covered everything. I'm sure there will be questions and we will address those one by one, but for the most part, I believe you have all the information needed to take full advantage of your tuner in 2008.

In part 4, I asked, "With what I have told you, can you give me the formula for adjusting the tuner to compensate for changes in density altitude?"

I have had no response to this question. :mad: Either I'm not a very good teacher or some of you haven't been paying attention. :rolleyes: But,,, no problem,,, I'll tell you anyway; listen up!

Once you find the optimum tuner setting by using the procedure outlined in part 2, you can maintain that in-tune condition with the following formula:

If density altitude goes up (weight of the atmosphere decreases) the tuner goes IN and vice versa. Move the tuner one eighth of a turn for each 250' change in DA. For example;

Let's say your rifle was perfectly in tune during the first match of the day. DA was 3000 ,tuner setting 12:00 o'clock. Arriving at the firing line for the second match of the day, you notice DA has increased to 3500. What do you do? :eek: That's right, you turn the tuner IN to the 9:00 o'clock position. Got it? GREAT! :D

One thing that I must remind you of and that is, I can gaurantee this formula will work only with my tuner, which is available to everyone. If your tuner is of a different design, uses a different thread pitch or different weight, you will have to work out your own formula the way I did; by trial and error.

Thank you all for listening; best of luck to you this year at the matches. :D

Later,,

Gene Beggs
 
Gene

The tuner you've developed sounds great...certainly appears to be simple to adjust for changes in D/A...My question is have you installed this tuner design on several barrels to determine that it will work the same on a HV taper at 22" as well as a LV taper at 20-3/4...a 13.5 twist and a 14 twist...etc..
:confused:
 
Thanks Gene,

...as of yet I do not employ a tuner but my thanks to you for sharing your knowledge not only regarding tuners but also all aspects of Benchrest shooting!...........Be well, shoot well........... Jan
 
Gene

It appears that a change of .10 in the baro, from 28.80 to 28.70 for example is worth about 93 feet in DA. Also, a change in temp of 5 degrees is worth roughly 310 feet. A simple radio shack Baro/temp guage can be used. It won't tell you what the DA is, but it will let you determine how much it has changed.
Bryan
 
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Good for you Eddie,,

eww1350 said:
The tuner you've developed sounds great...certainly appears to be simple to adjust for changes in D/A...My question is have you installed this tuner design on several barrels to determine that it will work the same on a HV taper at 22" as well as a LV taper at 20-3/4...a 13.5 twist and a 14 twist...etc..
:confused:
Click to expand...

,,that's a question I hoped someone would ask.

Yes, I have used my tuners on several different barrels chambered in both 220 and 6mm Beggs, HV and LV contour. I have tried twist rates of 13, 13.5 and 14 in lengths from 19" to as long as 27". All barrels have reacted exactly the same to tuner adjustments. I have not experimented with unlimited barrels, although I plan to do so. I am expecting them to require more weight.

Many believe there is only ONE magic setting and/or weight that will work for each individual barrel and that is not the case. A tuner such as mine that threads onto the muzzle AFT of the crown, should be thought of as a focus ring, not a counterweight. Such a tuner enables the shooter to vary the barrel's vibration frequency at will.

Each barrel vibrates at its own specific frequency due to length, diameter, taper, etc. If it's a good barrel and installed correctly, it vibrates almost entirely in the verticle plane; the muzzle slows and comes to a complete stop at both the top and bottom of its swing.

Of course by now, all of you understand that in order to get the rifle in tune, we must time bullet exit to coincide with one or the other of these stops, but best accuracy is usually obtained when the bullets exit at the top stop.

The reason my tuner works with so many different barrel lengths and contours is the fact that we must only vary the frequency slightly to change bullet exit timing. Let's say our bullets are exiting at mid swing; the rifle is completely out of tune and tuner setting is 12:00 o'clock. Since the range of the tuner is one revolution we must turn the tuner a half turn to be in tune, but,do we turn the tuner IN a half turn or OUT a half turn; either way the tuner winds up in the 6:00 o'clock position? We know that if we place the tuner at the 6:00 o'clock position, our bullets will exit at one of the stops, but,,,,,"Which one, Vern,,,top or bottom?" :confused: :mad:

Some of you may be thinking, "Damn, this stuff is getting too complicated for me; to hell with it!" If that's the case, just take a little break and get away from it for a while. Your subconcious will continue working on it and soon, it will become clear to you. This may be a little advanced for you at this time but don't worry, I certainly did not learn this overnight.

Later,,

Gene Beggs
 
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Gene, Do ya think - -

The tuner will work on an HBR barrrel?
 
Installation of tuner...

Gene, when you sell a tuner to a customer will you send written installation instructions?
Would you recomment putting the barrel between centers and truing a 2" flat from the muzzle back, then thread required thread pitch and diameter?
Are you going to offer installation?
 
It appears that a change of .10 in the baro, from 28.80 to 28.70 for example is worth about 93 feet in DA. Also, a change in temp of 5 degrees is worth roughly 310 feet. A simple radio shack Baro/temp guage can be used. It won't tell you what the DA is, but it will let you determine how much it has changed.
Bryan
Click to expand...

Bryan

Please excuse my lack of knowledge, but what formula do you use to determine the amount of change?

Tony
 
Tony

My figures are probably not totally correct, and I'm sure Gene will make me stay after school if they are not.:eek:
I used a pressure altitude compensation chart, and a Koch chart. Both of which are used by pilots.
The PACC chart shows the pressure altitude difference when the barometric pressure changes. The Koch chart actually shows Density Altitude, but requires you to know the pressure altitude and temp. I think doing it this way is fairly accurate, and requires less equipment.
Bryan
 
eww1350 said:
Gene, when you sell a tuner to a customer will you send written installation instructions?
Would you recomment putting the barrel between centers and truing a 2" flat from the muzzle back, then thread required thread pitch and diameter?
Are you going to offer installation?
Click to expand...

Eddie all three of your questions are easy to answer. Yes, yes and yes. :D

Later,

Gene Beggs
 
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