Tuning with tuners part 2

R

Richard

Member
Been working with a few BR shooters and felt that a few things needed to be brought to light to help those tuning with tuners. Once the basics are down this is what I'm seeing from new shooters. Lets say they shot a group and had a bullet of vertical. They turn the tuner and shoot a flat group but it has some horizontal in it. I hear them say, that is just the way a tuner works. That is not the case. What is needed is some load tweaking. To make it simple the most important thing to get rid of the horizontal is seating depth. If you have pure vertical and tune it to shoot a dot and it has horizontal you need to adjust seating depth. When the seating depth is perfect you can go from pure vertical to a dot with no horizontal.
Other things will come into play such as neck tension, neck to chamber clearance and a few other things.
The tuners I work with will not affect the horizontal if the seating depth is perfect. If it is not it will.

Richard
 
Re: Tuners Part 2

Richard,
Thanks for taking the time to help those of us who are taking the tuner journey.
You along with Mike and Gene have helped open my eyes to a whole new world!
So far I am having great success with my modified palma profile LV barels and find the results repeatable and somewhat predictable.
My current procedure when I chamber a new barrel is to fireform, then start with my pet load of LT32 with seating depth at jam. (No tuner)
I go .4grns on either side of my pet load in .1 grn increments, verify the middle of the node and then work on seating depth to get rid of the vertical.
Usually I find two sweet spots, Jam to .005 off Jam (still in @ .015) and just off touch (@ .025 off jam).
The just off touch seems to have a wider "window" on the tuner usually.
Once I do this then the tuner goes on and I dial in the sweet spot from there.
I have a couple of questions:
a: It sounds to me from what you are saying is that during load development I should be tuning out the horizontal with seating depth until I get straight vertical,
and then dial this out with the tuner?
b: Do you do all of this initial tuning with no tuner, and then dial out the vertical with the tuner on? If so do you still find you need to tweak the seating depth again?

Once again I appreciate you taking the time help us on this fascinating journey.
Greg
 
Greg, you can

find the correct seating either way, tuner on or off the gun. I find it just as easy with the tuner installed so I'll explain what I want to see and how to get there fairly quickly.
On a new bbl the first thing you need find is where your at on the tuning node. I set mine to where when you turn the tuner inward the vertical gets less. Shoot some 3 shot groups. Let's say it just shot a dot. Now take the gun out of tune by about .003 movement and see what you get. If it's pure vertical great, but it probably won't be. Now leave the tuner where it's at and start playing with the seating depth until you get pure vertical. One thing to be aware of is if your changing seating depth by .003 or more you might have to tweak the tuner a small amount to keep the same tune you started with.
You can also find what you want working the opposite side. Lets say the gun has vertical and you turn the tuner and get a flat but wide group. Leave the tuner alone a tweak the depth until it shoots a dot. Now turn the tuner to put vertical in the group and see if it's pure vertical.
It sounds complicated but it's really not once you get the feel for it. It helps to have a general idea of what the bullets like from previous bbl.'s if possible.
What I have found is the die from which the bullets were made determine the seating depth more than the barrel. One die I use makes bullets which like to be seated into the lands around .007 and the final tweak will be plus or minus .003 at the extreme. Another die I use likes to be into the lands around .020 plus or minus a few thou. These are 65-68's on .825 jackets.

I see the same thing for the PRS guys. Had a customer call who was shooting at 800 yds with a 6 dasher and getting flat but really wide groups. He was jumping .010 at the start and as he went more off the lands the groups narrowed down.
Hopefully this makes sense, a lot harder to explain on the keyboard than actually showing somebody how quick and easy it really is once you get a feel for it.

Richard
 
What I have found is the die from which the bullets were made determine the seating depth more than the barrel. One die I use makes bullets which like to be seated into the lands around .007 and the final tweak will be plus or minus .003 at the extreme. Another die I use likes to be into the lands around .020 plus or minus a few thou. These are 65-68's on .825 jackets.
Richard[/QUOTE]

Richard thanks for the informative response!
I also have found that the sweet spot for seating depth seems to remain in "roughly" the same spot regardless of barrel (with the caveat that I am using the same reamer and brand/twist barrels) but varies with the configuration of the dies. My bulletmaker is very OCD and gives me samples of different things he is trying, and the results are interesting. I am not sure if subtle differences in ogive shape, point up, core seating pressure, are causing this effect. Some things seem to work, some don't.
What I need is a 200 yd tunnel and some sophisticated test equipment along with some eggheads to interpret the data for me.
Or I guess I could quit being so OCD and just read the targets and watch the wind flags:rolleyes:, but what's the fun in that?

Once we get back to shooting out here in the Peoples Republic, I plan to try the method you use on a new barrel as well as a known barrel and see how it works.
I will let you know what I find out.
Regards,
Greg
 
Interesting

I'm in the thick of this.
I think I went the long way but
I'm knocking on the door !
I'm at the "get it set and forget it"....
I don't know what to do with it now.
 
May I suggest that

you do a search on this forum. There is a a huge amount if good info on here on how to use a tuner. Read through them and try some of the ideas presented here. If after that your still having issues post your problems.

Richard
 
Richard, you always amaze me with your tuner savvy. I've never even been gutsy enough to own one and you have them figured out. I'm going to have to get me one. I can't shoot any worse.
 
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