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I would highly recommend that you abandon your current tuning method (which will never give you a precise result). This is what I have had 100% success with...
1. Install 12 ounces of Riverside weights.
2. Create a 'tuning target' (8-1/2" x 11" card stock). Draw 5 horizonal lines all the way across the width of the paper (landscape), and then draw short vertical hash marks onto those horizontal lines creating a multi-lined grid. Make several copies of your master tuning target and keep your original in a safe place.
3. Label the first hash mark '80'. This is going to be the first tuner setting that you will shoot. The second hash mark will be '85', the third will be '90', and so on until you reach '140' on the first horizonal line.
4. Shoot a three-shot group at each hash mark.
5. Analyze the groups you just fired for two things - the first is the size of the groups, the second is the formation of the sine waves. Use a circle template to draw circles around each group. Then use a french curve to draw curves through all the groups. You will see sine waves developing as you draw these curves. Be very precise when you do this!
6. In my experience, the smallest groups will form where the sine wave was either near the top or near the bottom of the wave. Remove one Riverside ring (2 ounces) if you feel that none of the groups are 'small'. And then repeat the same routine on the second hash line.
7. Reshoot those groups (three - 3 shot groups) that were the smallest and were near the top or bottom of the sine wave. It is paramount that you shoot at least three - 3 shot groups for confirmation! You will understand why when you do this.
8. After you have settled onto a setting or two, hang an ARA target and shoot it. It has to be at least a 2350 or better to conclude that you have a 'confirmed' tuner setting.
9. All this has to be performed on a calm day of course. The temperature is not a determining factor.
10. I also recommend that you have either a Don Blue Tube or one of the 'lighter' tubes that Killough Shooting Sports carries. I say this because you may find that the addition of a tube to the Riverside weights may produce smaller groups. That is my experience.
Good luck!

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41 Posts
Discussion Starter · #22 ·
Read up on this thread. I use my spreadsheet to calculate my tuning. The best setting for me was to match the bullet body length to the quarter wavelength of the standing wave and dampening the frequency response of the barrel base on the inverse of the time it takes the bullet to exit the crown of the barrel.
Will do and Thank
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