tuners and data

[Apollo]

I do not own a tuner, but am considering the idea. I have a few things that need to be worked out, one of which is data keeping. Do you guys, that use tuners, tune to: temp alone, temp and humidity, temp humidity and pressure, etc. If you tune to more than one variable is there a formula that you use to come up with "1 number" that you can corrispond to your tuner?
If this question has already been asked - please don't reinvent the wheel - just point me to the previous discussion.

Thanks for your time

Jason Stanley

[jackie schmidt]

I have been using a tuner for over four years, with a certain amount of success.

I would like to say that I use all sorts of data from sophisticated instruments when deciding what to do, or when to do it, but the simple fact is, if the Rifle acts like it is trying to get ragged, I just turn the thing about 1/2 turn, toss some shots down range on the sighter, and see what happens.

Probably not the answer you want, but more times than not, it works.

As with a lot of things, you can overcomplicate the situation. I just keep it simple.......jackie

[FBecigneul]

He will tell you he (and I ) tune according to the density altitude. Sorry to tell you, I don't know of any other way to determine DA than to get a Kestrel instrument. I have a Kestrel 4000.

[Apollo]

I'm glad both of you responded. Francis, density altitude? I am assuming that is the density of the air at a certain altitude. On your Kestrel 4000, does it give you a number and then you correspond that number to previous practice groups then adjust your tuner accordingly? I'm interested in the tuner on my upcoming 30BR barrel used mainly for score, but the only way it will help me is if I can predict what it needs to be set at before I shoot each match. And...I'm not sure if I am a good enough shot to know if the 1 bullet of verticle is me missreading the wind or the tune.
Jackie & Francis, during an actual match - do you have to adjust your tuners much? Meaning - does the 30BR need to be tuned based on conditions - or just tune the load to the barrel once and "forget it"?

Thanks again for your time. Sorry so many questions - but I am really good at doing things twice and three times - problem is takes a lot of money to do that. Would be a heck of a lot cheaper just to do things once.

Stanley

[FBecigneul]

a number of settings and their performance at given DAs. It is a straight like graph. It takes some time as you can't create DA. I fine tune about every other match or sooner if conditions change enough to warrant it. We marked our barrels near the tuner and numbered them from 9 o'clock to 3 o'clock. A change of two hundred fifty on the Kestrel has a value of about one hour on the Beggs tuner. You can fine tune between the hour settings. When we get to 3 o'clock we just turn back to 9 o'clock again rather than proceed much between 3 and 9 o'clock. The Beggs tuner weighs 4 ounces and we have it threaded on the barrels close to the muzzle. We left enough ahead of the threading in case we re-crown. Turning the barrels down in front of the threading and then the removal of metal for the threads accounted for much of that 4 ounces so the weigh gain was negligible.

[Gene Beggs]

I do not own a tuner, but am considering the idea. I have a few things that need to be worked out, one of which is data keeping. Do you guys, that use tuners, tune to: temp alone, temp and humidity, temp humidity and pressure, etc. If you tune to more than one variable is there a formula that you use to come up with "1 number" that you can corrispond to your tuner?
If this question has already been asked - please don't reinvent the wheel - just point me to the previous discussion.

Thanks for your time

Jason Stanley

Hello Jason

Francis and Jackie have done such a fine job of explaining how to use a tuner, I don't have much to add.

Francis is correct; decrease in air density, (increase in density altitude, DA) primarily the result of increase in temperature, is what makes our rifles go out of tune. As ambient air temp increases, the air thins out. (DA increases) Thinner air results in less atmospheric resistance as the bullet travels down the bore and the bullets begin to exit early, before the muzzle has come to a complete stop. If we tune with the powder charge, we would decrease the charge to restore bullet exit timing. If we have a tuner, we can screw the tuner toward the breach end of the barrel, which increases vibration frequency. Rather than slow down the bullet, we speed up the barrel. Make sense?

Some people try to make too much of adjusting a tuner. I tend to be more like Jackie Schmidt, I like to keep things simple. When I go to the line, no matter where I am or what the DA is, I know I can't be more than a half turn out of tune. I have a zero setting for my tuner and that's where I'll always start. I'll fire a test group and see where I am and make whatever change it takes to bring the rifle into tune, noting the temp and tuner setting. If temp goes up five degrees, I know I must turn the tuner IN an eighth of a turn to keep in tune.

Think about this for a while and get back to me if you have any questions.

I have tried tuning with the powder charge and with a tuner; I've gone back and forth three or four times and can state with certainty that tuning with a tuner is far easier than chasing the load.

Later

Gene Beggs