Two nodes
- Thread starter Boatninja
- Start date
Did you happen to shoot multiple rounds through chrono for each charge?
I look at ES for nodes more than anything else.
Here is an example:
I look at ES for nodes more than anything else.
Here is an example:
I’m still fumbling around with this stuff. It’s a good excuse to shoot!
I’ve found that depending on the primer, you may not see a flat spot in velocity.
My 6gt with cci 450’s usually continues to climb on average 12fps for every .2 charge increase.
So, I don’t even really pay attention to the actual velocity. I make not of it for informational purposes. But I only use ES now for nodes.
My 6gt with cci 450’s usually continues to climb on average 12fps for every .2 charge increase.
So, I don’t even really pay attention to the actual velocity. I make not of it for informational purposes. But I only use ES now for nodes.
So in gr above, I’d be looking at 32.6, 33.8, and 34.8. Pick a node and start testing seating depth.
You see those curves?
The points where the curvature reverses, either upward or downward, indicate the nodes.
What this signifies is that within that curvature reversal, velocity deviations have less effect on accuracy. The more sharply vertical, the more effect; the more horizontal, the less effect.
That's what a node is.
You can get this info from a chrono, or you can get it from the target.
From the chrono, that info is statistical, and needs a lot of data points before it becomes reliable. Those data points also represent degrading bore life. The conclusions are really just an extrapolation, and not actual performance ontarget.
The target is direct, not an extrapolation; and the target just about never lies.
I have a use for my chrono. I use it when load development is done; in order to extrapolate trajectory performance from the resultant muzzle velocity. It only tells part of that story, too.
It makes zero reference to atmospheric conditions downrange. In essence, once the bullet gets downrange by a few feet, all bets are off without also incorporating those additional factors.
We didn't always have chronos. That lack didn't keep us from shooting accurately. It has been made more accurate, and more complex with the addition. Every time we add a step to a process, we also add another opportunity to make a mistake.
Greg
The points where the curvature reverses, either upward or downward, indicate the nodes.
What this signifies is that within that curvature reversal, velocity deviations have less effect on accuracy. The more sharply vertical, the more effect; the more horizontal, the less effect.
That's what a node is.
You can get this info from a chrono, or you can get it from the target.
From the chrono, that info is statistical, and needs a lot of data points before it becomes reliable. Those data points also represent degrading bore life. The conclusions are really just an extrapolation, and not actual performance ontarget.
The target is direct, not an extrapolation; and the target just about never lies.
I have a use for my chrono. I use it when load development is done; in order to extrapolate trajectory performance from the resultant muzzle velocity. It only tells part of that story, too.
It makes zero reference to atmospheric conditions downrange. In essence, once the bullet gets downrange by a few feet, all bets are off without also incorporating those additional factors.
We didn't always have chronos. That lack didn't keep us from shooting accurately. It has been made more accurate, and more complex with the addition. Every time we add a step to a process, we also add another opportunity to make a mistake.
Greg
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I fumbled around for about my first 8 years making ammo before I was confident I "knew what I was doing". And I'm still learning.
I've been handloading for accuracy since around 1994. I got into it by working with my Elder Brother who was a rabid BR shooter. His zeal and disregard for expenditures of time and money scared me a little, and largely led to my diversion into the more 'practical' disciplines.
I've since translated my need for the word "Ultimate" into a need for the word "Adequate".
BTW, I like your new avatar.
Greg
I've since translated my need for the word "Ultimate" into a need for the word "Adequate".
BTW, I like your new avatar.
Greg
If you tightly control your loading process, you can do it with a chrono with far less data.
For example, when doing load development, I make sure every shoulder is bumped the same, all the necks are uniform, neck tension is checked on all with a pin gauge, a hydro press used to verify seating pressure consistency, and every round measured from BTO.
So, there is little reason to believe my data is going to vary enough over the long term as there just isn’t anywhere for inconsistencies to occur.
You obviously know a universe more than I do. And with all due respect you are talking way over my head. Is there anything useful in my graph? I am working with what I have and a range that only goes to 200yds so it is hard to work up the loads by targets. I do have a chronograph. I don’t compete or have funds to shoot enough to even be concerned about barrel life, to say I had shot out a barrel would be a glory day.
Ninja;
My commentary was not meant as an attack or even as a disagreement. I solely attempting to translate a graphic into a simple explanation.
Dthomas;
We're also in pretty near complete agreement. I don't have access to pin gauges, and have come to dread lugging more gear, including tripods and chronos, all the way down (50 miles) to the range; I'm already lugging too much as it is, and I'm no longer a reliable pack mule.
About 15 years ago, my Wife and I got handed a few unpleasant surprises that make the key factor in our lives one of simplicity. My key strategy has been about still getting what I want while complying with all of that folderol.
Perfection plays no role. It's overkill.
Live long and prosper! I do...
Greg
My commentary was not meant as an attack or even as a disagreement. I solely attempting to translate a graphic into a simple explanation.
Dthomas;
We're also in pretty near complete agreement. I don't have access to pin gauges, and have come to dread lugging more gear, including tripods and chronos, all the way down (50 miles) to the range; I'm already lugging too much as it is, and I'm no longer a reliable pack mule.
About 15 years ago, my Wife and I got handed a few unpleasant surprises that make the key factor in our lives one of simplicity. My key strategy has been about still getting what I want while complying with all of that folderol.
Perfection plays no role. It's overkill.
Live long and prosper! I do...
Greg
Greg makes a good point I tend to forget about.
If you’re not controlling your loading tolerances tightly, you’ll need to shoot larger batches over the chrono.
If you’re not controlling your loading tolerances tightly, you’ll need to shoot larger batches over the chrono.
THAT is the key that some, mainly new(er) reloaders, don't realize. Consistency doesn't apply just to the fundamentals of marksmanship. But to the reloading process, too.
I don’t take it as a attack, far from it, I just am not comprehending whether any of you guys see anything there. I am so novice (and far from young) that I take anything as constructive.
Happy to help, may I help you further?
Oh, and yes; 42.2, and 43...
What round/load are we commenting on; because it looks like a dead ringer for my own 7.62x51/175SMK/IMR-4064 load. Back in the day (late 1990's) I had written it up in Precision Shooting.
GI 7.62x51 NATO brass (these days IMI), 175SMK at 2.815" COAL, Large Match Primer (I use CCI BR-2), and 42.2gr of IMR-4064.
Greg
Oh, and yes; 42.2, and 43...
What round/load are we commenting on; because it looks like a dead ringer for my own 7.62x51/175SMK/IMR-4064 load. Back in the day (late 1990's) I had written it up in Precision Shooting.
GI 7.62x51 NATO brass (these days IMI), 175SMK at 2.815" COAL, Large Match Primer (I use CCI BR-2), and 42.2gr of IMR-4064.
Greg
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I'd be interested in reading your article. If you still have it or possibly a link.
6mm Creedmoor, 105gr Berger Hybrid Federal 210m primer and Staball 6.5 powder, any more info you require I would be glad to provide. It appears I was correct in my assessment that you know a Universe more than I do. I value the knowledge that such as yourself have but please reply in terms that a novice can understand
Are those individual shots that you are using for data points or are those averages of more than one data point?
If individual shots, how do you know if they are actually low in relation to other charge weights or are they only low in relation to the total variance of the load itself?
If individual shots, how do you know if they are actually low in relation to other charge weights or are they only low in relation to the total variance of the load itself?
So would I like to read it/them, too.
My computer from back then is cratered.
I gave all my copies of Precision Shooting and Tactical Shooter to my longtime shooting partner back around 2005.
He had an epiphany, and dropped off the planet.
Those copies are long, long, gone.
Missed, too...
Greg
RIP Precision Shooting...
Dave and Kim are good people from out of my past...
They did the whole thing. All of us contributors simple sent Dave a floppy, and got a check, probably, some time after.
Simpler is better.
Some of it is still in print, sorta.
My computer from back then is cratered.
I gave all my copies of Precision Shooting and Tactical Shooter to my longtime shooting partner back around 2005.
He had an epiphany, and dropped off the planet.
Those copies are long, long, gone.
Missed, too...
Greg
RIP Precision Shooting...
Dave and Kim are good people from out of my past...
They did the whole thing. All of us contributors simple sent Dave a floppy, and got a check, probably, some time after.
Simpler is better.
Some of it is still in print, sorta.
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I don’t understand the graph but I have been writing down all shot data, I will try to work up averages
Basically what he’s saying is if it’s a single shot, it’s unknown if the velocity data is in the high, middle, or low end of you ES in that given load.
Exactly this:
The blue dots are individual shots, the orange dots are the averages at each charge weight, the rectangle enclosed all of the shots for that sample.
Are the dots in your graphs
A) averages of many shots making a sufficient amount of data to provide an accurate representation of the true behavior or
B) individual data points where the shot you sampled could just be the low shot outlier of what’s really going on like was circled?
I would do a minimum of 3 shots. If you don’t do a ton of brass prep or QC checks, I’d do 5 or 10 each.
