Tuners some info.

geo.ulrich

geo.ulrich

Member
This will probably get some interesting response's. after talking yesterday wiyh Larry Fuesse about tuners and what they are adjusting to or for i decided to try something originally we talked about calculating the coefficient of expansion for s.s. 440r. i decided to check a barrel itself. i used a 30 cal. hunter class taper 24.00 inches long. stood on granite surface plate and set hite gage and indicater. indicater was set at 0 at 69.4 degree's.i warmed barrel and checked with a infared thermometer allowing time to soak and temps. to equalize by checking at 4 locations along the barrel. at 69.4=0,85= +.008, 91= +.0135, 105= +.0215, 112= +.026, 120= +.030. so are tuners being adjusted for atmosphere or just expansion. george
 
The barrel grew in length by .030 with a 50.6 degree change....wow....wouldn't have thougth that much. Now George......knowing how talented you are. Can you measure bore diameter expansion/contraction and outside diameter?

Interesting info you provided.

Hovis
 
Kevin, yes the outside dia.calculation isn't to big of a jump but the bore will expand not contract. george
 
True. Once the temperature has stabilized the bore will be larger.
However, IF the barrel is being heated from within the bore, the initial transient change will be a reduction in bore diameter since the metal at the bore will have been heated and grown in size but the outside steel has not yet caught up with it and is still forcing it to the inside. This will remain the case so long as the bore is at a significantly higher temp than the outside of the barrel. It's a transient effect, but should not be overlooked.
 
George

That is very interesting. I would have never thought a barrel would grow that much in length with what is really a small temperature change.

As for your tuner question, I have never taken into consideration the temperature of the barrel. In all honesty, I never thought to. But if one turn of a tuner on a 32 tpi can change the tune, it would stand to reason that .030 longer in barrel length would have someaffect. How much?? I don't have a clue.

What I have been doing with my tuners as of late is putting a "pet load" in the Rifle, one I know that a particular barrel-bullet-powder combo likes, and tune it with the tuner to optimize the potential.

Last week end, I installed one of the new Bartlien Gain Twist on my LV-Sporter, and just stuck 31.8 grns of 8208 BRX in. It stared out with about 1/4 inch of verticle, I turned the tuner twice, settling in on about 1 1/4 turn from the originol, and it tightened right up. I then shot three straight "mid ones". I am pretty pleased at the moment.......jackie
 
To Vibe...

No, if you heat any portion of the barrel, inside or outside you will always cause the diameter to increase. The expansion you think would cause the bore to come in occurs over such a small radial dimension, it just can't offset the expansion you get in the circumferential direction. The outer portion of the barrel that is not heated doesn't just sit there and push the bore into a smaller diameter - it is in tension which means it has been stretched to a larger diameter. You need to calculate the numbers to see what is really happening.
 
pacecil said:
No, if you heat any portion of the barrel, inside or outside you will always cause the diameter to increase. The expansion you think would cause the bore to come in occurs over such a small radial dimension, it just can't offset the expansion you get in the circumferential direction. The outer portion of the barrel that is not heated doesn't just sit there and push the bore into a smaller diameter - it is in tension which means it has been stretched to a larger diameter. You need to calculate the numbers to see what is really happening.
Click to expand...
Been there done that. It was around 1983 or so - as college assignment - I can't remember if it was Physics or Mechanics of Materials. The results were just as I've stated. Not that it makes a lot of difference on the scale being discussed, but even a steady state temperature rise does not cause the bore dimension to change measurably.
@ 0.00000645in/in/deg F° there is just not enough affected material to make much difference. Much less than 1/2 a tenth per 100°F difference between bore and OD.

But yes the effect is very easily contained to the interior so long as there is a substantial temperature gradient between a hot bore and a much cooler outside diameter. In a thick wall tube with 1000°F inside and less than 100°F outside - there is a considerable temporary gradient. The thicker the wall the more pronounced the effect, for the reasons you pointed out of course.
pacecil said:
The outer portion of the barrel that is not heated doesn't just sit there and push the bore into a smaller diameter - it is in tension which means it has been stretched to a larger diameter.
Click to expand...
Just because the bore circumference in in compression and the Outside is in tension does not mean that the OD has stretched ENOUGH to prevent bore reduction - there is a lot more steel on the outside than there is on the inside, and hot steel is not as strong - by 800° it will have lost fully 1/2 it's strength, but that's a more extreme case than what we're talking here, although it's a very real factor in why a rifle throat takes on a flaky appearance in it's aging process, it's actually being pushed to the yield point in compression by the sudden flashes of fire.
 
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Very Interesting!

geo.ulrich said:
This will probably get some interesting response's. after talking yesterday wiyh Larry Fuesse about tuners and what they are adjusting to or for i decided to try something originally we talked about calculating the coefficient of expansion for s.s. 440r. i decided to check a barrel itself. i used a 30 cal. hunter class taper 24.00 inches long. stood on granite surface plate and set hite gage and indicater. indicater was set at 0 at 69.4 degree's.i warmed barrel and checked with a infared thermometer allowing time to soak and temps. to equalize by checking at 4 locations along the barrel. at 69.4=0,85= +.008, 91= +.0135, 105= +.0215, 112= +.026, 120= +.030. so are tuners being adjusted for atmosphere or just expansion. george
Click to expand...



George, you bring up a very good point; one that I had not considered. The fact that the barrel gets longer when heated could explain some of the surprises I have had during the past couple of years. :eek:

I have done a fair amount of experimenting with tuners in the tunnel and feel that I have the best one on the market. The Beggs tuner weighs only four ounces. It is inexpensive, easy to adjust, locks up securely on the barrel and does not interfere with muzzle blast or result in changes in point of impact when adjustments are made.

During developement, I found that within reason, weight of the tuner is unimportant but the amount it is moved fore and aft on the barrel is! :eek:

The tuner is much like the 'steel' used in playing a steel guitar; the musician places the steel on the strings and moves it fore and aft to vary the tone. Move the steel toward the breech and the tone rises and vice versa. Same thing with the tuner; move it toward the breech and the vibration frequency increases, move it toward the muzzle and the frequency decreases. It doesn't seem to matter whether the steel/tuner weighs four ounces or six; the result is the same.:eek:

The big question is,,,

"If the test group on the sighter shows the rifle is completely out of tune, how far do you move the tuner? Which way; in or out? One turn; two and a quarter, what?" :eek: Good question; huh?

It is common knowledge that the Beggs tuner has a one revolution range from one node to the next and that the farthest you can be out of tune is a half turn. The thread is .875-28 tpi. 28 tpi results in .036 movement in one revolution, so a half turn of the tuner moves it only .018. :eek: George, you have found that the barrel grows in length by .030 when heated from 69 degrees to 120 degrees and it only takes .018 movement of the tuner to throw the rifle completely out of tune! :eek: Whoa buddy!! You have opened a completely new can of worms! :eek: In your post above you asked,

"so are tuners being adjusted for atmosphere or just expansion?" george[/QUOTE]

Prior to reading your post above, I would have answered, "Atmosphere only" but after thinking about the little nuclear bomb you just dropped on us my answer would be, "BOTH." :eek: :)


The following question has been asked thousands of times and has been discussed here on the forum until most don't want to hear anything more about it. The question is, "What causes our rifles to go out of tune?"

The answer is, "ANYTHING." Anything that is, that alters bullet exit timing. The rifle is in tune when bullet exit coincides with muzzle stop. The muzzle stops twice in each vibration cycle; at the top and bottom of the swing.

George, we must discuss this in greater detail. I think you have hit on something very significant and my simple little tuner is the solution. :) We focus our scopes quickly and easily by turning a focus ring, now we can focus our barrels the same way. :D

Later

Gene Beggs
 
"During developement, I found that within reason, weight of the tuner is unimportant but the amount it is moved fore and aft on the barrel is!"

I disagree. I believe the weight of the tuner is VERY important. I'm not saying that a any particular weight is the key weight, just that heavier tuners (within reason) require less adjustment, less often. I also feel that just as strongly about the majority of the tuner weight being beyond the muzzle as opposed to being behind it.
 
Hal D. said:
"During developement, I found that within reason, weight of the tuner is unimportant but the amount it is moved fore and aft on the barrel is!"

I disagree. I believe the weight of the tuner is VERY important. I'm not saying that any particular weight is the key weight, just that heavier tuners (within reason) require less adjustment, less often. I also feel that just as strongly about the majority of the tuner weight being beyond the muzzle as opposed to being behind it.
Click to expand...


Hal, I would like to extend to you an invitation to join me in the tunnel for some tuner demonstrations. :)

There are those who disagree with me but are unwilling to back up their claims by showing me. I, on the other hand am ready, willing and able to back up what I say with real world, real time demonstrations in the tunnel.

Please understand, I'm not a pretentious person and I don't claim to know it all. All I can do is show you what I have learned the hard way; trial and error.

I hope you will accept my invitation to come to Midland/Odessa, TX and see for yourself. The Midland International Airport is served by both American and Southwest Airlines. I can pick you up and in twenty minutes we will be at the tunnel where we can shoot in comfort with no wind. No need to bring equipment; we can shoot my rifles. What do you say? :)

Gene Beggs
 
Gene

Gene Beggs said:
George, you bring up a very good point; one that I had not considered. The fact that the barrel gets longer when heated could explain some of the surprises I have had during the past couple of years. :eek:

I have done a fair amount of experimenting with tuners in the tunnel and feel that I have the best one on the market. The Beggs tuner weighs only four ounces. It is inexpensive, easy to adjust, locks up securely on the barrel and does not interfere with muzzle blast or result in changes in point of impact when adjustments are made.

During developement, I found that within reason, weight of the tuner is unimportant but the amount it is moved fore and aft on the barrel is! :eek:

The tuner is much like the 'steel' used in playing a steel guitar; the musician places the steel on the strings and moves it fore and aft to vary the tone. Move the steel toward the breech and the tone rises and vice versa. Same thing with the tuner; move it toward the breech and the vibration frequency increases, move it toward the muzzle and the frequency decreases. It doesn't seem to matter whether the steel/tuner weighs four ounces or six; the result is the same.:eek:

The big question is,,,

"If the test group on the sighter shows the rifle is completely out of tune, how far do you move the tuner? Which way; in or out? One turn; two and a quarter, what?" :eek: Good question; huh?

It is common knowledge that the Beggs tuner has a one revolution range from one node to the next and that the farthest you can be out of tune is a half turn. The thread is .875-28 tpi. 28 tpi results in .036 movement in one revolution, so a half turn of the tuner moves it only .018. :eek: George, you have found that the barrel grows in length by .030 when heated from 69 degrees to 120 degrees and it only takes .018 movement of the tuner to throw the rifle completely out of tune! :eek: Whoa buddy!! You have opened a completely new can of worms! :eek: In your post above you asked,

"so are tuners being adjusted for atmosphere or just expansion?" george
Click to expand...

Prior to reading your post above, I would have answered, "Atmosphere only" but after thinking about the little nuclear bomb you just dropped on us my answer would be, "BOTH." :eek: :)


The following question has been asked thousands of times and has been discussed here on the forum until most don't want to hear anything more about it. The question is, "What causes our rifles to go out of tune?"

The answer is, "ANYTHING." Anything that is, that alters bullet exit timing. The rifle is in tune when bullet exit coincides with muzzle stop. The muzzle stops twice in each vibration cycle; at the top and bottom of the swing.

George, we must discuss this in greater detail. I think you have hit on something very significant and my simple little tuner is the solution. :) We focus our scopes quickly and easily by turning a focus ring, now we can focus our barrels the same way. :D

Later

Gene Beggs[/QUOTE]

Gene, I'm going to throw a monkey wrench into this and ask for your thoughts on this. If my gun is in tune at 60 degrees ambient temp with a cold barrel and a warm barrel, doesn't that debunk this theory? That is what I have seen. I can shot 1 group or several at a given ambient temp and tune, and still be in tune. The tune doesn't seem to change as the barrel warms considerably. Tune does change somewhat though with different ambient temps. That's my experience, and I shoot alot of sighters at times with the gun staying in tune no matter how many I shoot. Your thoughts would be appreciated.--Mike Ezell
I would add to that, that I have recrowned my barrel by recessing the crown by about .030 and seen no change in tune. I have also done it and seen great improvement(crown worn?)
 
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Boyd Allen said:
Does any of this cast liquid recirculating barrel coolers in a new light?
Click to expand...

That's my point Boyd. I for one, don't think so...yet. I am open to evidence to the contrary though. From what I see on the target, I'm not ready to buy this as "how tuners work".---Mike Ezell
 
Mike Ezell [/QUOTE] Gene, I'm going to throw a monkey wrench into this and ask for your thoughts. If my gun is in tune at 60 degrees ambient temp with a cold barrel and a warm barrel, doesn't that debunk this theory? That is what I have seen. I can shot 1 group or several at a given ambient temp and tune, and still be in tune. The tune doesn't seem to change as the barrel warms considerably. Tune does change somewhat though with different ambient temps. That's my experience, and I shoot alot of sighters at times with the gun staying in tune no matter how many I shoot. Your thoughts would be appreciated.--Mike Ezell [/QUOTE]


Mike, you know me, I'm always looking for ways to simplify things; I no longer pay any attention to ambient temperature, density altitude or anything else. I let the rifle tell me if it is in tune or not. I know I cannot be more than half a turn out of tune under any circumstances. I go to the line with the same load regardless of conditions, fire a test group and see where I am. I know I have a one in four chance of being in tune. Sometimes I get lucky and the test group shows no vertical but the way my luck usually runs, I'll be at least a quarter of a turn out of tune in one direction or the other. :(

Let's say the test group on the sighter shows one bullet hole of vertical, which indicates a quarter turn out of tune, but which way? Who cares? Simply give the tuner a quarter turn in either direction and fire a three shot test group. If you luck out and go the right direction, the test group will show no vertical. If you went the wrong way it will show two bullet holes of vertical which indicates a full out of tune condition. Give the tuner a half turn in EITHER direction and the rifle will be in tune. :D

That's all there is to it. :cool: As long as the rifle doesn't show any vertical you're in tune; don't change anything. But if vertical begins to creep in you can be sure you will have to turn the tuner IN to compensate. How much? Try a quarter turn to begin with and fire a three shot test group. The rifle will ALWAYS tell you whether or not it's in tune. No need for any fancy equipment, charts, knowledge of density altitude, relative humidity, phase of the moon etc. You don't need any of that to focus your scope; do you? No, of course not and you don't need all that stuff to focus your barrel either.

Go to the line and get the rifle in tune as I described above and as long as it continues to shoot well with no vertical dispersion that cannot be attributed to wind and/or mirage, leave it alone; don't change nothing. :)

Hope this helps.

FWIW

Gene Beggs
 
geo.ulrich said:
This will probably get some interesting response's. after talking yesterday wiyh Larry Fuesse about tuners and what they are adjusting to or for i decided to try something originally we talked about calculating the coefficient of expansion for s.s. 440r. i decided to check a barrel itself. i used a 30 cal. hunter class taper 24.00 inches long. stood on granite surface plate and set hite gage and indicater. indicater was set at 0 at 69.4 degree's.i warmed barrel and checked with a infared thermometer allowing time to soak and temps. to equalize by checking at 4 locations along the barrel. at 69.4=0,85= +.008, 91= +.0135, 105= +.0215, 112= +.026, 120= +.030. so are tuners being adjusted for atmosphere or just expansion. george
Click to expand...

George,
Something seems fishy with these measurements. The coefficient of thermal expansion for 440r is 5.78e-6 per degree F (http://www.440c.co.uk/tech.php). Your 24" barrel should have grown 0.007" over 50.6F.

Cheers,
Keith
 
Gene

That's all I do. I just turn the darned thing untill the Rifle starts shooting like a Benchrest Rifle. The non metalic tuner I have on my LV-Sporter, (made from Nylatron), only takes about a turn one way or the other to find it.

I think shooters over complicate this. If I thnik the Rifle is getting ragged, I will toss a couple of 3 shot groups on the sighter and adjust accordingly. I have been doing this for over four years now, with a good amount of success.......jackie
 
Gene Beggs said:
The rifle is in tune when bullet exit coincides with muzzle stop. The muzzle stops twice in each vibration cycle; at the top and bottom of the swing.
Click to expand...

Gene,
You need to read VarmintAl. You will experience an epiphany.:)

Cheers,
Keith
 
Gene Beggs said:
Mike Ezell
Click to expand...
Gene, I'm going to throw a monkey wrench into this and ask for your thoughts. If my gun is in tune at 60 degrees ambient temp with a cold barrel and a warm barrel, doesn't that debunk this theory? That is what I have seen. I can shot 1 group or several at a given ambient temp and tune, and still be in tune. The tune doesn't seem to change as the barrel warms considerably. Tune does change somewhat though with different ambient temps. That's my experience, and I shoot alot of sighters at times with the gun staying in tune no matter how many I shoot. Your thoughts would be appreciated.--Mike Ezell [/QUOTE]


Mike, you know me, I'm always looking for ways to simplify things; I no longer pay any attention to ambient temperature, density altitude or anything else. I let the rifle tell me if it is in tune or not. I know I cannot be more than half a turn out of tune under any circumstances. I go to the line with the same load regardless of conditions, fire a test group and see where I am. I know I have a one in four chance of being in tune. Sometimes I get lucky and the test group shows no vertical but the way my luck usually runs, I'll be at least a quarter of a turn out of tune in one direction or the other. :(

Let's say the test group on the sighter shows one bullet hole of vertical, which indicates a quarter turn out of tune, but which way? Who cares? Simply give the tuner a quarter turn in either direction and fire a three shot test group. If you luck out and go the right direction, the test group will show no vertical. If you went the wrong way it will show two bullet holes of vertical which indicates a full out of tune condition. Give the tuner a half turn in EITHER direction and the rifle will be in tune. :D

That's all there is to it. :cool: As long as the rifle doesn't show any vertical you're in tune; don't change anything. But if vertical begins to creep in you can be sure you will have to turn the tuner IN to compensate. How much? Try a quarter turn to begin with and fire a three shot test group. The rifle will ALWAYS tell you whether or not it's in tune. No need for any fancy equipment, charts, knowledge of density altitude, relative humidity, phase of the moon etc. You don't need any of that to focus your scope; do you? No, of course not and you don't need all that stuff to focus your barrel either.

Go to the line and get the rifle in tune as I described above and as long as it continues to shoot well with no vertical dispersion that cannot be attributed to wind and/or mirage, leave it alone; don't change nothing. :)

Hope this helps.

FWIW

Gene Beggs[/QUOTE]

Gene, I agree with everything you said, and have found tuners to be simple and east to use(except in bad conditions) but I didn't see a direct response to the question. I'm not trying to put you on the spot, just trying to pick YOUR brain a bit as you have done the research. Have you SEEN a difference in tune after shooting several shots(enough to warm the barrel) versus a few shots? I haven't.--Mike Ezell
 
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