Target free ladder test?

[Dave Way]

While it may be possible to identify a velocity flat spot, the number of reported observations used are always too few as you suggest. And it will require more to achieve suitable average velocity results ( like n=10) than relying on the target where 1 or 2 shots per charge for a ladder are suitable. Amazingly a few years ago the loading world was set on fire by the guy espousing 1 shot per charge to find the chrono flat spot, amazing illogical nonsense.

I appreciate your response as well as the responses from Webster and others. My data was based on averages and extreme spreads from three rounds per charge. I understand more representative data could be obtained with more shots per charge. It’s not going to happen with this barrel as it is showing potential to possibly shoot down into the ones at 1K and I have no interest in wasting barrel life.

With that being said, until someone can show me stronger evidence that “velocity flat spots” don’t exist, using whatever number of shots you think make the data irrefutable, I need to remain skeptical. I have seen it too many times. Since I wasn’t attempting to prove or disprove the theory it may have only been three or five shots per charge but I have seen it just the same. Coincidence? Maybe, maybe not.

Thanks again for your input,
Dave.

 

[Bc'z]

I'm with David on this.
Targets dont lie in that you can definitely see POI in a rather horizontal line aka "flat spot"
Or should I refer to it as
minimal vertical dispersion.
I agree multiple shots to confirm a load, but when someone is searching out the node for their given combination more than 3 shots IMO is a waste of components and barrel life.

 

[CharlieNC]

I appreciate your response as well as the responses from Webster and others. My data was based on averages and extreme spreads from three rounds per charge. I understand more representative data could be obtained with more shots per charge. It’s not going to happen with this barrel as it is showing potential to possibly shoot down into the ones at 1K and I have no interest in wasting barrel life.

With that being said, until someone can show me stronger evidence that “velocity flat spots” don’t exist, using whatever number of shots you think make the data irrefutable, I need to remain skeptical. I have seen it too many times. Since I wasn’t attempting to prove or disprove the theory it may have only been three or five shots per charge but I have seen it just the same. Coincidence? Maybe, maybe not.

Thanks again for your input,
Dave.

I do not deny that a velocity flat spot might exist, but that the noise requires a considerable number of shots to obtain a suitable average from which to make a reliable conclusion. Especially those who espouse one shot is enough is simply bunk. But more importantly if the target does not display a vertically flat node at the same charge as the velocity, then you have a major issue. Barrel harmonics leading to this vertical behavior is well known. I am not a ballistics expert, but I have difficulty understanding why velocity would exhibit a node at the same charge as the harmonic behavior. Some day soon I plan to answer this to my satisfaction.

 

[Dave M.]

I don't shoot in competition. I don't use R2 to develope loads. I shoot at targets. If you plotted the average fps for a large number of shots at each load the you should be able to draw a straight line thru the data points, no flat spot. More powder more fps with an ES spread. Charts with flat spots only exist because you are plotting a small number of shots at each load and it ignores the fact that the ES for 10 shots would be bigger and more accurate and the average fps would be more accurate. One shot at a load may be at the high end of the ES, you increase the powder and the next shot is at the low end of the ES. They are not flat because something unique is happening that allows no or little increase in fps with a powder increase. To sum everything up ignore flat spots and determine accuracy by looking at targets. There are no short cuts. Tony Boyer is the best short range BR shooter that ever lived he developes and tunes his loads by his targets. He has about 100 Hall of Fame points more than his nearest competitor. I only put the charts up to prove there is no real flat spot.

WOW….I just reread this from a few years ago and I couldn’t agree with this anymore. People want to find the flat spots so bad that some of them will only shoot 2-3 shots at each charge weight and then point to a “flat spot”. I hope more people read this post Webster made 2+ years ago and take it to heart.

 

[mikecr]

You see a powder node with a chronograph.
You see a barrel node on target.
It's few that line up together.

 

[Doom]

You see a powder node with a chronograph.
You see a barrel node on target.
It's few that line up together.

Great post Mike!

 

[wedgy]

Vertical Dispersion: Flat spots on the MV ladder test are meaningless

Just looking at the info you presented? Loads 14,15, and 16 would have gotten my attention.

forum.accurateshooter.com

 

[RegionRat]

You see a powder node with a chronograph.
You see a barrel node on target.
It's few that line up together.

That is about as short and sweet as I have ever seen it put into words.