Gene Beggs
Active member
Good morning gentlemen.
We have now covered tuner basics and learned the procedure for getting our rifle in tune, now let's move on to the real 'nitty gritty' of the subject and answer the BIG question;
"Which way do you move the darn thing, and how far do you move it when DA goes up 250 feet, 500 or even 1000?"
I've heard this question a hundred times or more and have told many exactly how to do it, but my advice usually goes in one ear and out the other and I am dismissed as just another crackpot that doesn't know what he is talking about. Here is the truth.
Let's say that during the extra three minutes alloted for match one, we followed the procedure outlined in part 2 and got our rifle perfectly in tune and noted density altitude and tuner setting.
We are back at the line for the second match and notice that temperature has increased by five degrees and a glance at the DA meter shows an increase of 500 feet. This means our bullet will encounter less atmospheric resistance as it accellerates down the bore. In-bore time will be decreased, which will result in bullet exit before the barrel comes to a complete stop.
In years past, we would reduce the powder charge to compensate, but today, with the advent of tuners, we can compensate by increasing the frequency of the barrel. That's right! Moving the tuner toward the breech end of the barrel increases vibration frequency and vice versa. If you have trouble remembering which way to go the following gouge may help.
"DA goes up, frequency must go up to stay in tune."
"Okay",,you say,,,"Now I know which way to go with the darn thing; if temp goes up, relative humidity goes down, density altitude goes up, and Wilbur's blood pressure increases (sorry Wilbur, couldn't resist
), turn the tuner toward the breech end of the barrel, (Up in, down & out) but how much, Vern,,, how much?"
With the tuners I have been working with in the tunnel for the past several weeks, the range is one revolution. That's right, if there were enough threads, and you turned the tuner out through several revolutions, you would encounter a sweet spot every 360 degrees. Expressed in density altitude, this corresponds to two thousand foot increments. Let's say you have your rifle perfectly in tune at sea level; the tuner is set at 12:00 o'clock. You then magically levitate you and your rifle to a density altitude of 2000 feet making no changes whatsoever to the load or tuner; your rifle will still be in perfect tune.
So,,,,,let's say our rifle was perfectly in tune an hour ago when DA was 3000 feet and the tuner set at 12:00 o'clock. Now, an hour later, DA has increased to 3500. It will be necessary to turn the tuner IN to 9:00 o'clock to remain in tune.
Now,, that wasn't so hard; was it? Of course not. DA goes up, tuner goes in. "up & in, down & out"
Now with what I've told you, can you tell me what the formula is for adjusting the tuner throughout the day?
Later,,
Gene Beggs
We have now covered tuner basics and learned the procedure for getting our rifle in tune, now let's move on to the real 'nitty gritty' of the subject and answer the BIG question;
"Which way do you move the darn thing, and how far do you move it when DA goes up 250 feet, 500 or even 1000?"
I've heard this question a hundred times or more and have told many exactly how to do it, but my advice usually goes in one ear and out the other and I am dismissed as just another crackpot that doesn't know what he is talking about. Here is the truth.
Let's say that during the extra three minutes alloted for match one, we followed the procedure outlined in part 2 and got our rifle perfectly in tune and noted density altitude and tuner setting.
We are back at the line for the second match and notice that temperature has increased by five degrees and a glance at the DA meter shows an increase of 500 feet. This means our bullet will encounter less atmospheric resistance as it accellerates down the bore. In-bore time will be decreased, which will result in bullet exit before the barrel comes to a complete stop.
In years past, we would reduce the powder charge to compensate, but today, with the advent of tuners, we can compensate by increasing the frequency of the barrel. That's right! Moving the tuner toward the breech end of the barrel increases vibration frequency and vice versa. If you have trouble remembering which way to go the following gouge may help.
"DA goes up, frequency must go up to stay in tune."
"Okay",,you say,,,"Now I know which way to go with the darn thing; if temp goes up, relative humidity goes down, density altitude goes up, and Wilbur's blood pressure increases (sorry Wilbur, couldn't resist
), turn the tuner toward the breech end of the barrel, (Up in, down & out) but how much, Vern,,, how much?" With the tuners I have been working with in the tunnel for the past several weeks, the range is one revolution. That's right, if there were enough threads, and you turned the tuner out through several revolutions, you would encounter a sweet spot every 360 degrees. Expressed in density altitude, this corresponds to two thousand foot increments. Let's say you have your rifle perfectly in tune at sea level; the tuner is set at 12:00 o'clock. You then magically levitate you and your rifle to a density altitude of 2000 feet making no changes whatsoever to the load or tuner; your rifle will still be in perfect tune.
So,,,,,let's say our rifle was perfectly in tune an hour ago when DA was 3000 feet and the tuner set at 12:00 o'clock. Now, an hour later, DA has increased to 3500. It will be necessary to turn the tuner IN to 9:00 o'clock to remain in tune.
Now,, that wasn't so hard; was it? Of course not. DA goes up, tuner goes in. "up & in, down & out"
Now with what I've told you, can you tell me what the formula is for adjusting the tuner throughout the day?
Later,,
Gene Beggs
