Tuning "on the fly"

W

Wilbur

cook and bottle washer
There's been a couple or three threads lately (actually, ongoing for many years) concerning the effects of humidity, "DA", etc...on the "tune" of our rifles. I confess that while I changed my load when I wasn't shooting well, I didn't use anything as a basis - I just changed it to something different. More often than not, the change either made matters worse or had no effect. Now and then, I would find a cookie that improved my scores.

That said, one fine day I screwed on a barrel that shot well regardless of the weather, wind, and load. All I had to do was pick out a reasonable condition, shoot five bullets and go get my pine board(s).

My question is....Why did this barrel/rifle combination accept any and all conditions while others need "tuning" as they go?
 
it knew the benchrest song......
hum along with me.....
hummmmmmmmmmmmmmmer

i think, dangerous, that it was a combination of your load, a great bbl and a excellent chambering job.
( as not all gunsmiths chamber "excellent" al the time, it was a case where his technique happened to hit the throat perfect)

just 2 cents worth
mike in co
 
Wilbur.....My first brand new barrel(Shilen),chambered by a reputable gunsmith,made me believe I knew how to shoot Benchrest. When that barrel died,reality struck real hard. My next new barrel convinced me that I didn't know shiit. I'm still looking for a barrel like that first one. Wish I knew the answer.

Glenn
 
Wilber
I don't think we know enough yet about what is involved in tuning a rifle system to definitively answer that question - too much disinformation has been disseminated. I'm of the opinion that a barrel, once tuned, is always tuned - and cannot be tuned, until everything else is right. There are probably other "adjustments" that can be made - load development being one of them - that can influence the performance. But I don't think that "twisting" on a tuner (of current design) is really one of those adjustments that can be reliably done "on the fly", with repeatable and predictable results.
 
If we knew that, barrel makers might stand a chance of making more that are that way. We don't, so they can't. Personally, I think that the stress relieving process might be an issue. If it is, I know of no way to "look" at a finished barrel to sort on that basis.
 
Wilbur said:
There's been a couple or three threads lately (actually, ongoing for many years) concerning the effects of humidity, "DA", etc...on the "tune" of our rifles. I confess that while I changed my load when I wasn't shooting well, I didn't use anything as a basis - I just changed it to something different. More often than not, the change either made matters worse or had no effect. Now and then, I would find a cookie that improved my scores.

That said, one fine day I screwed on a barrel that shot well regardless of the weather, wind, and load. All I had to do was pick out a reasonable condition, shoot five bullets and go get my pine board(s).

My question is....Why did this barrel/rifle combination accept any and all conditions while others need "tuning" as they go?
Click to expand...
That was Paul Wolfs old barrel!!
 
Yeah.....

Chism G said:
Wilbur.....My first brand new barrel(Shilen),chambered by a reputable gunsmith,made me believe I knew how to shoot Benchrest. When that barrel died,reality struck real hard. My next new barrel convinced me that I didn't know shiit. I'm still looking for a barrel like that first one. Wish I knew the answer.

Glenn
Click to expand...

Yeah...I'm still looking for a barrel that shoots where I want; not where I aim it....virg:rolleyes:
 
My question is,

In the US especially, the areas that have HUGE temp swings in the day is that not one of the main reasons you need to supposedly constantly tweek your loads???

I find that in our cooler climate it APPEARS that our loads are more stable. We just feel that since we do not have the temp swings our loads do not go south as bad.

But, what do I know? Maybe we need to get a few of you southern fellas to come up to Canada and tell us if it is or is not so...............

Just my thoughts.

Calvin
 
have you ever seen a barrel thats faster than other barrrel's.. say as much as 200FPS faster.. what causes that? And why?
could it be a fast barrel that has a broader tune window..does not need as much powder to hit the velocity needed to exit the bullet at the right barrel vibration.
so it tunes easyer and stays in tune over more temp changes.. could it be a velocity thing?
 
CYanchycki said:
My question is,

In the US especially, the areas that have HUGE temp swings in the day is that not one of the main reasons you need to supposedly constantly tweek your loads???

I find that in our cooler climate it APPEARS that our loads are more stable. We just feel that since we do not have the temp swings our loads do not go south as bad.

But, what do I know? Maybe we need to get a few of you southern fellas to come up to Canada and tell us if it is or is not so...............

Just my thoughts.

Calvin
Click to expand...

Actually, areas that have the lowest humidity also experience the biggest temp swings. So it's kind of a catch 22 for figuring out how to tune based on either temp, or humidity, or both. Around my neck of the woods, it's quite common for the temps to be in the mid 50's to low 60's in the summer mornings and then go up to 95 during the day. As the temp climbs, what humidity we do have usually goes lower still. So I tune completely based off of temp and temp alone. When I've heeded the "eastern" advice of volume powder dispensing more in the mornings and less in the afternoons to compensate for RPH and powder adsorption, I've had horrible results nearly every time.. If I go off nothing but the thermometer and throw more in the morning and less in the afternoon by weight or by volume, I've done much better. That being said, I compete in matches basically only in the mid-continent and southwestern regions where altitudes are high and humidity is low. The only exception to this is Phoenix which is 1600' elevation and can have high humidity and high temps. Nearly every time I've shot there, I've had to go down on powder charges compared to what I shoot at home (4500'). That may be due to humidity but it could also be due to higher temps. That's what makes this so hard to figure out..............how do you seperate which factor is causing your results when both factors go hand in hand and can't be singled out under normal conditions?? If we could keep the humidity exactly the same with some kind of humidifier in a tunnel while we cranked up the AC or turned on the heat, or, keep the temp the same while we change the settings on the humidifier........then we might have some data that we could understand! Until then, we tweek things as we go and try to do the best we can.
 
A tune in time saves a whine

Disclaimer: The following is personal opinion and may bear no relation, in many peoples opinion, to reality.
A well tuned rifle is critical in our sport. A good set up, good shooting platform (rifle), good barrel and bullets is easy to tune as was the rifle mentioned at the beginning of this thread. Any other combination is a nightmare to tune and keep in tune. Irregardless you must try. Here are some hints that have worked for me. Boat tail bullets are very sensitive to seating depth at least for me and they are what I shoot. A difference of .002" is important. 133 powder is difficult to keep in tune and 8208 (not XBR 8208) is less so. (I have been unable to get XBR to shoot well for me.). Take several loads to the line and try them on the sighter if you are not doing well. Your gun may be going out of tune or not be in tune. One bad group may be your fault. Two in a row is a warning of equipment/tune problems. If you cannot get your gun to shoot don't be afraid to change bullets, powder or if possible guns. Pay attention to what others are shooting but don't relay totally on their advice. Look at trends not individuals. Use what works for you even if it bucks the trends. If you are doing poorly and every one else is not you may want to change to what they are doing. If you are doing well ignore them even if you are the lone ranger in what you are shooting. Results are far more important then opinion. Finally have faith in yourself. You can do it. If you are not succeeding try something different rather then throwing in the towel and exclaiming "I cannot shoot worth a d__n. I am a failure". Sooner or later the benchrest gods will smile on you and you will do well. Tim
 
Wow......

Such words of wisdom from the FUNNY man himself.

I just want to say thanks Tim for your words of encouragement. In reading your post I would have thought you were describing me.

I just may have to print this out and stick it in my range box...................................

Calvin
 
There are a few guys out there who have put in the time with tuners to find out how much to turn them to stay in tune. I saw a shooter do it just last weekend. Tuner settings are a lot more subtle than many think and it takes going to the range a number of days in different temp and humidity swings to find out how much or little to turn them. KEEP GOOD NOTES! USE THEM!

One can go pre-laded and simply adjust their tuner to stay in tune. A lot of Score Shooters go pre-loaded and some of them know when and which way to turn the tuner, according to how the test groups in the sighter look and from the results of their testing.

I gave up on tuners with CF rifles because I never seemed to find the time to go to the range a lot to test and find the answers. I had hoped, by now, someone would have developed and published a chart but I have yet to see one. I am willing to pay quite a bit for a reliable chart, when one comes along.

I see the same thing with RF rifles. I don't buy the theory that once a rifle is tuned, it's tuned. I see my rifles go out of tune almost every match. I think a lot more can be done with tuners. One just has to believe moving the tuner is the answer.
 
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Dear Goodgrouper, I shoot my BT bullets about .004 to .006 into the lands. This is in a cut rifle barrel. I use a bullet coated with magic marker to get the touch point and go into the lands from there. Be aware that getting the touch point is difficult. It takes a little bit of trial and error. Good luck to you in this endlessly fascinating and frustrating sport of benchrest. Tim
 
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Uncle Jerry,,, I bleeb that was the original barrel Clarence Hammonds put on the gun. Keith Gant couldn't lose w/it. Just point and shoot. Wilbur bought it and became instant "pine board magnet" Paul Wolfe had great barrel also. He set 200 yd agg record (HV) and won the South East Region championship. Once Paul, shooting @ Unaka , had a bullet go out of group , for no apparent reason. I ask what happened,,, he said "its that damn wind,, I know it is" then he said,, yeeeaaaa
JerrySharrett said:
That was Paul Wolfs old barrel!!
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What about the guy in Dublin Ga.? He loaded 200 shells/cartridges in middle Georgia, a week before Super Shoot. He won the Super Shoot that year. Was that a turned rifle, that stayed tuned, or just a well built, rifle /barrel combination. He always did well w/that barrel and rifle. (That was his first and last Super Shoot) I haven't heard of anyone pre-loading and doing well @ the Super Shoot. His first name was Ed,, can't remember his last name. Wilbur can tell us his name.
 
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