Tuners some info.
- Thread starter geo.ulrich
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M
mks
Guest
Mike,
I found that external barrel temperature on my 30BR increases surprisingly little above ambient temperature, and then only around the first few inches forward of the chamber. If I remember correctly (should have written everything down), just a few degrees near the barrel/action junction and at the muzzle, and less than 10F forward of the chamber. Measurements on a few rifles on neighboring benches showed the same. Since I haven't found a plausible mechanism for why ambient temperature alone should affect tune, my hypothesis is that barrel temperature is the important factor, but the temperature of a thick BR barrel follows ambient temperature so closely that it makes it seem like ambient temperature is important.
This article (www.shootingsoftware.com/ftp/Pressure Factors.pdf) demonstrates that barrel temperature and cartridge/powder temperature affect pressure, the author suggests by quenching the energy in the flame. There is likely some scientific research that proves or disproves this mechanism, but I haven't had time to look into it. It makes sense to me, FWIW.
Cheers,
Keith
Boyd Allen
Active member
I can see it now, electric barrel heaters plugged into little generators up and down the line, while shooters share tips about what starting temperature is working the best. Ready on the right, ready on the left, remove heaters, insert bolts, commence fire.
M
mks
Guest
Boyd,
Just my opinion, but I think if you could keep the temperature of the gun and ammo constant, tune would not change. Connect a constant temperature circulator (http://www.rheologysolutions.com/prodtemp.html) to the the fluid around the barrel and keep the ammo at controlled temperature, and shooters could preload, never touch the tuner, and have nothing to do between matches.
Cheers,
Keith
Gene Beggs
Active member
Mike Ezell[/QUOTE] Gene, I agree with everything you said, and have found tuners to be simple and easy 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[/QUOTE]
Mike, in answer to your question,
"Have you SEEN a difference in tune after shooting several shots(enough to warm the barrel) versus a few shots?"
Yes; yes I have. Let me explain.
This happened to me a number of times before I realized what was going on. When I first began using tuners, I would go to the line with a squeaky clean barrel, fire ONE fouler, then a three shot test group. If the test group showed no vertical, I went to the record. So many times before I finished the record group it showed a lot of vertical and I didn't know why; now I do. The squeaky clean barrel had not settled in; before the five shot record group was completed, the rifle was out of tune. I don't know how many times this happened to me before I finally figured it out. After screwing up the record group, I often went back to the sighter, re-tuned the barrel and then shot a screamer on the sighter. Bummer! So, what is the answer to the problem? Simple; don't clean during an agg and don't be too quick to declare the rifle in tune after a thorough cleaning.
Extensive chronographing in the tunnel has shown that a perfectly clean barrel continues accumulating fouling for about eight or ten shots before velocity settles down. If you clean after each relay, you are starting over from scratch every time you go to the line. If you do not clean between relays, you can trust the barrel to deliver consistent velocities and stay in tune.
Sometimes we go to the line and just as the range officer says "Commence Fire" conditions are perfect. If your barrel is already fouled and ready to go, you can go right to the record target and steal a screamer. But if you have to spend the first three or four minutes fouling and tuning the barrel, the condition will be gone.
The great majority of benchrest shooters believe that you MUST clean your barrel after EVERY group and that if you do not, accuracy will suffer. This is nonsense. After the first match of the day, the barrel is just settling in to deliver consistent muzzle velocities. If you clean it, you're starting all over again. My normal procedure is to start a five match agg with a clean barrel and I do not clean until that agg is finished.
I realize there are those who are saying, "Beggs, you're crazy!" but I know what I'm talking about and have proven it on the line in competition. At the NBRSA Nationals in Phoenix in 2003, I won the HV Grand with a .1851 agg. I started the agg with a clean barrel and did not clean until the agg was finished. My last group at 200 yards was .228!
Some will ask, "But if I don't clean after every eight to ten shots, won't I hurt my barrel?" No! Absolutely not. Most shooters do far more harm to their barrels with cleaning than by shooting.
Others will say, "Beggs, I know you think you know what you're talking about but I have seen accuracy go to pot after ten or twelve rounds." Sure they have because the rifle just happened to be in tune for the first five or six rounds and as it settled in after the ten or twelve rounds, it was out of tune with the load the shooter was using. That's the BIG advantage of using a tuner; you can adjust for an out of tune condition at the line!
Last weekend at the Cactus Classic in Phoenix, I was shooting beside Dee Myers. Ask him how my skeleton stocked rifle, "ol' Bud" was shooting at 200 yards on Sunday. And on that subject, I must confess to something that most benchresters will regard as an unpardonable sin. I did not clean my rifle one time the whole two day match. No, no,, please don't kill me! There is more!
Over coffee and breakfast last week, I told Cecil Tucker and Charles Huckeba about what I had done and invited them over to the shop to examine the barrel with a borescope. There was no copper anywhere and the barrel showed a normal amount of powder fouling which I believe is mostly graphite and other components from the powder coating. I believe this coating provides a barrier between the bullet jacket and bore which helps prevent copper fouling. I suppose this brings up even more questions.
1. What kind of powder were you using? 29 grains of Hodgdon's 322 Extreme.
2. What velocity were you shooting? 3380 to 3400.
3. What cartridge were you using? 6mm Beggs .269 NK.
4. What bullet were you shooting? Tucker 66 grain BT.
5. What primer? Wolf SRM
6. What kind of barrel is it? Old Hart setback with over 4000 rounds thru it.
Now,,, here's what I'm going to do. The barrel has not been touched since returning from Phoenix. Next week, I'll invite Tucker and Huckeba to come to the tunnel as witnesses and using the same load I shot in Phoenix, fire two or three groups to see if the barrel will still shoot.
That ought to be interesting; huh?
Later
Gene Beggs
Mike, in answer to your question,
"Have you SEEN a difference in tune after shooting several shots(enough to warm the barrel) versus a few shots?"
Yes; yes I have. Let me explain.
This happened to me a number of times before I realized what was going on.
When I first began using tuners, I would go to the line with a squeaky clean barrel, fire ONE fouler, then a three shot test group. If the test group showed no vertical, I went to the record. So many times before I finished the record group it showed a lot of vertical and I didn't know why; now I do. The squeaky clean barrel had not settled in; before the five shot record group was completed, the rifle was out of tune. I don't know how many times this happened to me before I finally figured it out. After screwing up the record group, I often went back to the sighter, re-tuned the barrel and then shot a screamer on the sighter. Bummer! So, what is the answer to the problem? Simple; don't clean during an agg and don't be too quick to declare the rifle in tune after a thorough cleaning.Extensive chronographing in the tunnel has shown that a perfectly clean barrel continues accumulating fouling for about eight or ten shots before velocity settles down. If you clean after each relay, you are starting over from scratch every time you go to the line. If you do not clean between relays, you can trust the barrel to deliver consistent velocities and stay in tune.
Sometimes we go to the line and just as the range officer says "Commence Fire" conditions are perfect. If your barrel is already fouled and ready to go, you can go right to the record target and steal a screamer.
But if you have to spend the first three or four minutes fouling and tuning the barrel, the condition will be gone. The great majority of benchrest shooters believe that you MUST clean your barrel after EVERY group and that if you do not, accuracy will suffer. This is nonsense.
After the first match of the day, the barrel is just settling in to deliver consistent muzzle velocities. If you clean it, you're starting all over again. My normal procedure is to start a five match agg with a clean barrel and I do not clean until that agg is finished.I realize there are those who are saying, "Beggs, you're crazy!" but I know what I'm talking about and have proven it on the line in competition. At the NBRSA Nationals in Phoenix in 2003, I won the HV Grand with a .1851 agg. I started the agg with a clean barrel and did not clean until the agg was finished. My last group at 200 yards was .228!
Some will ask, "But if I don't clean after every eight to ten shots, won't I hurt my barrel?" No! Absolutely not.
Most shooters do far more harm to their barrels with cleaning than by shooting. Others will say, "Beggs, I know you think you know what you're talking about but I have seen accuracy go to pot after ten or twelve rounds."
Sure they have because the rifle just happened to be in tune for the first five or six rounds and as it settled in after the ten or twelve rounds, it was out of tune with the load the shooter was using. That's the BIG advantage of using a tuner; you can adjust for an out of tune condition at the line! Last weekend at the Cactus Classic in Phoenix, I was shooting beside Dee Myers. Ask him how my skeleton stocked rifle, "ol' Bud" was shooting at 200 yards on Sunday.
And on that subject, I must confess to something that most benchresters will regard as an unpardonable sin. I did not clean my rifle one time the whole two day match. No, no,, please don't kill me! There is more! Over coffee and breakfast last week, I told Cecil Tucker and Charles Huckeba about what I had done and invited them over to the shop to examine the barrel with a borescope. There was no copper anywhere and the barrel showed a normal amount of powder fouling which I believe is mostly graphite and other components from the powder coating. I believe this coating provides a barrier between the bullet jacket and bore which helps prevent copper fouling. I suppose this brings up even more questions.
1. What kind of powder were you using? 29 grains of Hodgdon's 322 Extreme.
2. What velocity were you shooting? 3380 to 3400.
3. What cartridge were you using? 6mm Beggs .269 NK.
4. What bullet were you shooting? Tucker 66 grain BT.
5. What primer? Wolf SRM
6. What kind of barrel is it? Old Hart setback with over 4000 rounds thru it.
Now,,, here's what I'm going to do. The barrel has not been touched since returning from Phoenix. Next week, I'll invite Tucker and Huckeba to come to the tunnel as witnesses and using the same load I shot in Phoenix, fire two or three groups to see if the barrel will still shoot.
That ought to be interesting; huh?
Later
Gene Beggs
Last edited:
Gene Beggs
Active member
The Beggs tuner weighs 4 ounces. During developement, I built some that weighed as much as six ounces and tried mounting them both beyond and behind the muzzle. They all worked to one degree or another but the beyond the muzzle models caused significant changes in POI when adjusted.
As far as barrel length and contours are concerned, I have worked mostly with LV and Sporter rifles with lengths from 21 to 24 inches. All seem to respond exactly the same, but my friend Bryn Borras says my four ounce tuners do not work on his heavy varmint barrels. I'll have to do some experimenting in the tunnel using three rings instead of two on the HV rifles.
Mike in your post above you asked, "When building your tuner did you vary the amount of weight till you found adjustments that were... even? (for lack of a better word)
No not exactly; I experimented with different threads until I found one that resulted in exactly one revolution between nodes. I was delighted when I found that the actual weight was not critical but the distance moved was.
Hope this helps.
Gene Beggs
Gene Beggs
Active member
Gene,
You need to read VarmintAl. You will experience an epiphany.
Cheers,
Keith
Keith, I have followed all posts by Varmint Al. His computer and math skills make me look like an idiot but I have a keen understanding of things mechanical. I really enjoy Al's animated graphics and look forward to his posts.
Gene Beggs
Gene Beggs
Active member
Guys, reread George's post above and note that he stood his barrel on a granite surface plate and MEASURED the amount it grew in length with a precision instrument. You can't argue with that even though his results differ from what your calculations predict.
Gene Beggs
Gene Beggs
Active member
M
mks
Guest
Gene,
Sorry for being so cryptic. What I meant was that Al's website (varmintal.com) has a nice explanation of why bullets exiting when the muzzle is stopped (for instance, at the top or bottom of a vibration cycle) is bad for accuracy. Think about it. For a group of bullets with slightly different muzzle velocity and corresponding variation in barrel exit times, if the muzzle is stopped, then the slow bullets hit low on the target and the fast bullets hit high. The purpose of tuning is to try to get slow and fast bullets to strike the target at the same elevation. If you knew you were shooting a slower bullet, what would you do? Aim higher to compensate for the greater drop, right? That is exactly what you want the tuner to accomplish - to have the barrel automatically aim slower bullets higher. How can it do this? By having the bullets exit when the muzzle angle is rising. That way, fast bullets (which have shorter barrel exit times) exit sooner when the muzzle is pointed lower on the target, and slow bullets exit later when the muzzle is pointed higher. Pretty epiphanous, huh?
Cheers,
Keith
M
mks
Guest
Gene,
I would tend to agree, but the difference between theory and the measurements in this case is really large. Steel (including stainless) has coefficients that vary over a range of about 70%. Aluminum, brass and magnesium expand roughly twice as much as steel. But the measurements are showing the barrel expanding over four times as much as it should. Only some exotic metals like lithium expand that much. I wonder if the instrument was somehow affected by the warm barrel. Stranger things have happened. You know that a micrometer you keep in your back pocket (high temperature) will read differently than one you just pulled out of the tool chest.
Cheers,
Keith
Gene Beggs
Active member
Huh?
Keith, you educated guys are always confusing us old rednecks with them fancy words. Epi,, or is it, epofon,,, aw 'ell, I'll have to look it up. Standby
Okay, I brushed the dust off the old dictionary and found the words 'epiphany' and 'epiph,, or something like that had not even been invented when that dictionary was published. You gotta remember, I grew up out here in West Texas around farm and ranch folks; we have our own language and dialect. But as near as I can determine, if I had an epiphanous experience while reading Varmint Al's works I would more than likely respond with something like, "Well I'll be damned; I didn't know that!" Am I on the right track? Am I pretty close? Huh?
Seriously, I'm familiar with your explanation and that of Varmint Al and you may very well be right about what is happening. One thing for sure, when you get the load right, or in the case of a tuner, when you get it set right, groups shrink dramatically. Whether this is a result of the bullets exiting at the stops of the barrel or in mid swing is anyone's guess. I have no way of proving it one way or the other; however, experiments in the tunnel show that the in-tune condition coincides with the peaks and valleys of the sine wave that results from what I call, "Running A Line."
George Ulrich was sure right, this thread has generated some interesting responses; hasn't it?
Later
Gene Beggs
Gene,
Sorry for being so cryptic. What I meant was that Al's website (varmintal.com) has a nice explanation of why bullets exiting when the muzzle is stopped (for instance, at the top or bottom of a vibration cycle) is bad for accuracy. Think about it. For a group of bullets with slightly different muzzle velocity and corresponding variation in barrel exit times, if the muzzle is stopped, then the slow bullets hit low on the target and the fast bullets hit high. The purpose of tuning is to try to get slow and fast bullets to strike the target at the same elevation. If you knew you were shooting a slower bullet, what would you do? Aim higher to compensate for the greater drop, right? That is exactly what you want the tuner to accomplish - to have the barrel automatically aim slower bullets higher. How can it do this? By having the bullets exit when the muzzle angle is rising. That way, fast bullets (which have shorter barrel exit times) exit sooner when the muzzle is pointed lower on the target, and slow bullets exit later when the muzzle is pointed higher. Pretty epiphanous, huh?
Cheers,
Keith
Keith, you educated guys are always confusing us old rednecks with them fancy words.
Epi,, or is it, epofon,,, aw 'ell, I'll have to look it up. Standby Okay, I brushed the dust off the old dictionary and found the words 'epiphany' and 'epiph,, or something like that had not even been invented when that dictionary was published.
You gotta remember, I grew up out here in West Texas around farm and ranch folks; we have our own language and dialect. But as near as I can determine, if I had an epiphanous experience while reading Varmint Al's works I would more than likely respond with something like, "Well I'll be damned; I didn't know that!" Am I on the right track? Am I pretty close? Huh? Seriously, I'm familiar with your explanation and that of Varmint Al and you may very well be right about what is happening. One thing for sure, when you get the load right, or in the case of a tuner, when you get it set right, groups shrink dramatically. Whether this is a result of the bullets exiting at the stops of the barrel or in mid swing is anyone's guess. I have no way of proving it one way or the other; however, experiments in the tunnel show that the in-tune condition coincides with the peaks and valleys of the sine wave that results from what I call, "Running A Line."
George Ulrich was sure right, this thread has generated some interesting responses; hasn't it?
Later
Gene Beggs
I've always understood that the best area to shoot falls right below and behind the peak of a wave, where the barrel has stopped and is starting back down. POI is descending while velocity is rising.
al
Gene Beggs
Active member
Al you and Keith are probably right about this. Dr. Jack Jackson always tried to get this thru my thick skull but I never did quite understand.
And you know, it really doesn't matter because the barrel will tell me when it is in tune; it's smarter than I am. Al you and Keith are probably right about this. Dr. Jack Jackson always tried to get this thru my thick skull but I never did quite understand.
I got it from Borden....
Who worked w/Jackson and Vaughn et al.... I remember calling Jim in '97 or so and asking "but-but-but.... if the barrel's FALLING and the faster bullet gets there SOONER then how can it be that....????"
And proposing multiple bends, which Varmint Al's modeling later depicted exactly.
It all models and works.
now
al
T
tim in tx
Guest
gene sir
if you will let me ,and will drive to you to show you how these theories work that al and keith spoke of.i can bring the present barrel for a calibration standard and i can bring a brand new barrel [ intigrated tuner]and cut it back there and then .and you can shoot the gun.[6 dasher no brake].the intended result will be to see a bullet with one less grain of powder hitting .800 higher the normal load at 100 yds.that is how i would calibrate this new barrel for 1000yds and by that i am absolutly in tune for 1000yds only at all temps.i have not had to change a load from 58 to 103 degrees for the first time in my life and dont have to worry about es either .i know that sounds strange but it can be proven now.hope you can take me up on that offer sir.thanks tim in tx
if you will let me ,and will drive to you to show you how these theories work that al and keith spoke of.i can bring the present barrel for a calibration standard and i can bring a brand new barrel [ intigrated tuner]and cut it back there and then .and you can shoot the gun.[6 dasher no brake].the intended result will be to see a bullet with one less grain of powder hitting .800 higher the normal load at 100 yds.that is how i would calibrate this new barrel for 1000yds and by that i am absolutly in tune for 1000yds only at all temps.i have not had to change a load from 58 to 103 degrees for the first time in my life and dont have to worry about es either .i know that sounds strange but it can be proven now.hope you can take me up on that offer sir.thanks tim in tx
Gene Beggs
Active member
Right on Francis!
FBecigneul. Now said:Well said Francis.
Guys, I gotta' tell you a funny story about Francis.
Francis called one morning saying, "I always said I wasn't going to try a tuner until someone started beating me with one." Of course my question was, "Who did it?"
Yep, Matt came all the way from Michigan to learn how to use a tuner and he learned real good!
Sorry Francis, I just had to tell that.
Gene Beggs
Gene
I was giggling as I hit the submit button, as I felt we have been a little "tuner deficient" lately on the forum. Anyhow, I have my belief's about tuners and you have yours. Can't we all just get along???
I appreciate the invite to Texas, but I have a limited amount of time that I can be away. Between work and the match schedule, I don't have much spare time. Besides that, I prefer to do all my shooing in the "conditions" that I'll be faced with on match day. Matter of fact, I went all the way to the range today only to turn around and go home because of the complete lack of wind. I know, I know, your gonna say that testing should be done in a lab environment...I don't think so.
I believe that just about anything attached to the barrel can be used to "tune" it in one way or another. In my experience, a heavier tuner requires less adjustment than a lighter one. And you prove my point whenever you post about your tuners. You continue to point out that your always within a half a turn of being in tune. With my tuners, I've never been even close to a half turn out of tune. The farthest my tuners need adjusting is a quarter of a turn, to be in full on, competitive tune. Not only that, but I use 36 TPI instead of the 28TPI you use. As far as the beyond the muzzle comments...I have not had any kind of experience like you describe. You say that moving to the tuner creates large POI changes on the target??? You're talking to a guy that shoots his fair share of Score, Group and 600 yd matches. Group shooting is the ONLY discipline that a POI shift really doesn't mean all that much. I can assure you that a score shooter, as well as a LR shooter can't have major shifts in POI throughout the day. If a barrel is properly set up when chambering and crowning/threading, and the tuner is concentric, there will be no more a POI shift than there is when using your style tuner.
While I have made a few for a handful of shooters, I'm not in the market to make or sell tuners(its about as lucrative as making bullets). Allie and Lee Euber aren't that easy to impress, but they both own my tuners...
I was giggling as I hit the submit button, as I felt we have been a little "tuner deficient" lately on the forum. Anyhow, I have my belief's about tuners and you have yours. Can't we all just get along???
I appreciate the invite to Texas, but I have a limited amount of time that I can be away. Between work and the match schedule, I don't have much spare time. Besides that, I prefer to do all my shooing in the "conditions" that I'll be faced with on match day. Matter of fact, I went all the way to the range today only to turn around and go home because of the complete lack of wind. I know, I know, your gonna say that testing should be done in a lab environment...I don't think so.
I believe that just about anything attached to the barrel can be used to "tune" it in one way or another. In my experience, a heavier tuner requires less adjustment than a lighter one. And you prove my point whenever you post about your tuners. You continue to point out that your always within a half a turn of being in tune. With my tuners, I've never been even close to a half turn out of tune. The farthest my tuners need adjusting is a quarter of a turn, to be in full on, competitive tune. Not only that, but I use 36 TPI instead of the 28TPI you use. As far as the beyond the muzzle comments...I have not had any kind of experience like you describe. You say that moving to the tuner creates large POI changes on the target??? You're talking to a guy that shoots his fair share of Score, Group and 600 yd matches. Group shooting is the ONLY discipline that a POI shift really doesn't mean all that much. I can assure you that a score shooter, as well as a LR shooter can't have major shifts in POI throughout the day. If a barrel is properly set up when chambering and crowning/threading, and the tuner is concentric, there will be no more a POI shift than there is when using your style tuner.
While I have made a few for a handful of shooters, I'm not in the market to make or sell tuners(its about as lucrative as making bullets). Allie and Lee Euber aren't that easy to impress, but they both own my tuners...