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Originally Posted by 6.5x47 lapua
you have part of it but you are still thinking in terms of group shooting for long range shooting.whoever wrote positive compensation barrel tuning forms round groups at short distance which benefit long range shooting have no clue about what they are talking about.tuning rifles at distances or for distances requires tuning for the tightest vertical node at distance. most people shooting ladder tests have no idea what they are trying to accomplish in the first place because of all the misleading information circulating on the internet.
having seen,talked with,and shot against most all of the best long range shooters in the world the consensus is the same for tuning to shoot at distance.
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I am really not thinking of group shooting for long range shooting. I shoot 100 yard groups to confirm that the nodes, determined by the ladder tests, are going to shoot consistently under 1/2 MOA, at acceptable velocities and preferably with Low ES or SD. I then do what I believe is referred to as a "nodal tune" by going to smaller increments, trying different primers or seating depths.
However I believe that you are leaving the impression that Developing a Good Load, using this method, is not necessary as you can use a mechanical tuner to compensate. For most people developing loads to hunt to 600 yards this is adequate if they test the loads to that distance and find that they hold the 1/2 MOA group. I do believe that most people can learn what they are trying to accomplish if given proper guidance which is why I am posting the way I do it and further discussion is always welcome. If they become accomplished at finding a good load for their rifle and want to get into long range competition they will be ready for positive compensation tuning and may even do quite well going"bare".
I did a little more digging and found this information that suggests Nodal tuning can be quite effective to 500 yards+ especially if a tight group, with low ES is found. It may even be suggesting that it is a necessary first step?? I am learning and thank you for pointing the way.
I need to clarify testing at 500 yards. If you want a positive compensation tune, then you want a load that is sufficient to hold in at 500 yards and not be super tight in elevation terms because this is the approaching a middle distance of trajectory where compensation spreads are going to be greatest if you want the rifle to compensate at long range assuming you can identify the slow shots are going high.
If the group is super tight at 500 it may be compensating at that range and past that you enter a brief area of neutral compensation which drops off with greater elevation impact into negative compensation at long range.
If the tight group at 500 yards is a nodal tune it will remain tight if velocity has consistent low extreme spreads. But you run the risk of falling off the node should the atmosphere vary velocity.
I only use 500 yards to confirm 140 yard testing.
You may identify a starting point with incremental loads over a chronograph, plot these and prospect the flat spots in load development having done a primer test first with a safe pet load.
Here is an example of a load that I worked up in this way for one of my wildcats at 100 yards and the next increment above that opened up a bit.
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It did well at both 400 &500 Meters, except for horizontal dispersion due to wind. The first shot past 100yards is the one that nearly cut the center of the target and elevation was calculated using my Chrony results and RCBS load Exterior Ballistics Program with Berger's BC entered. The young fellow I sold the rifle and ammo to reported no trouble hitting to 950+ yards and even got a 4 1/"2 X 4 1/2" gong at that distance on the fifth shot. I believe that was with the holdovers I provided for the Zeiss conquest scope and shooting prone from a bipod for the first time. So yes a lot can be done, at 100 yards, to get most anyone started on the path to long range shooting even with a custom hunting rifle..
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