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