Strange day on the ladder test

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Sean,

I reckon I'm missing something here buuuut, the charge weights you have listed are in .3 gr. increments and the targets are in .1 gr. increments /ubbthreads/images/graemlins/confused.gif

It may be easier to mark shots in the order they fired ( 1, 2, 3, etc. ) and refer to your charge weight progression sheet that you loaded by . It is a lot easier to look for say .....1 through 25 with no decimals involved then on your test record bracket shots as they group on you target .

Jim B.
 
Yeah, the "S" looks a bit like a "5", but I do understand what you've got there.

Okay guys, what's the verdict? /ubbthreads/images/graemlins/laugh.gif

Dan
 
A little chrono data would be priceless here!! I'm still a novice on this ladder testing but I firmly believe that by watching the velocities on a chrono, one can arrive @ a very good combo for a rifle. This makes it very easy to spot the nodes, even if the groups on paper are not doing what you think they should.
 
Sean. Good thing you did the test yesterday. I went to the desert today ant the wind was hitting 20-25 mph. I didn't fire a shot. Gnoehuntingagain did shoot though and was whackin' the 408 yard gong with .308s and .223s with great regularity.

Try graphing the relative vertical position of your shots so you can see a trend or a pattern. Also graph your velocity. If I didn't do that with the ladder I shot a couple weeks ago I never would have made it to the next step. Once the shots were put in a neat order and I got some coaching the pattern I was looking for jumped out at me. I have yet to confirm this but the rounds are loaded and ready to try.

(I would do it for you but I'm exhausted and will be spending the remainder ofthe evening watching closing olympic ceremonies and sleeping.)

BTW we will have to get together and go to the desert an whack gongs this spring before it gets too hot and the snakes come out.
 
The only way to draw any tentative conclusions from those targets--and again--I emphasize tentative--is to assume that the wind carried some of the shots left and right, away from where they would have been in a calm wind. If you can pull certain shots which the chronograph showed had similar velocity to others which were stacking back into the stack--you could say "there's a node." But we of course don't know if the wind moved those shots, or if the barrel threw them over there.

I would humbly submit (and I know, humility isn't my strong suit /ubbthreads/images/graemlins/blush.gif ) that these two ladder tests are exhibit "A" in my case for the OCW method. And that is certainly not to impugn srhaggerty--it is simply to show that this test ends up yielding unintelligible results in many cases. I tried the ladder test myself--several times when I first began developing my own handloads. It's a crap shoot. Sometimes it works, and sometimes you just end up wasting bullets, powder, primers, barrel life--and time.

And before someone goes there, let me state that it is unfair and condescending for advocates of the ladder test to assert that when the results aren't readable that the shooter didn't know what he was doing... or the rifle has a substandard barrel. Sure, maybe that is the case some of the time, but certainly not all of the time.

Dan
 
Green. I want to say that I just made a post to you that may have caused me to be uninvited back to Lens livingroom. I composed it while you posted your last response. Upon reading your last reply I immeadiately deleted it. It had a lot to do with the sarcasm of your first two replies.

It also had a suggestion. This was it:

"Here is an idea that might be helpful and express your point of view. Draw a 1 MOA circle around the shots that are .5 grains backward from the max and (for sake of arguement ) assume that these circles represent the size of a 3 shot group shot round robin style. Then judging from the location of these hypothetical groups suggest an OCW load or range of loads to try to narrow the field."

I know you REALLY REALLY want to share the wonderfull things you believe the OCW will bring to the shooting world but shaggerty is trying to learn about the ladder test just as I am. I want to come to my own conclusions as to its viability. Then I and maybe sean will give the OCW a try.

You recently posted a well written bit on the value of experience. Well, sean and I and several others here are right in the middle of gaining experience doing ladder tests. I think it is unfair and condecending to repeatedly hyjack a thread on ladder tests by promoting the merits of a system you have developed when the question deals specifically with rounds that are already fired in persuit of learning of another system.

Like I suggested above, maybe you can at least help find an answer to seans question by applying your theories to the shots fired.
 
On the velocity numbers...

We can have extreme spreads of 60 or more feet per second with the same powder charge. I believe that we would all agree there...

So, since we know that the ES can stretch out there quite a bit--even when every cartridge has the same powder charge in it--we've got to stop and ask ourselves why we would let one particular velocity figure steer us toward or away from a particular cluster on the target. What I'm basically saying is that if, by virtue of a similar chronograph number, we "slide" a shot which we'd like to think would have been in a particular stack back into the group... or we toss out a shot that is right there in the group--but has an uncommon velocity--are we acting properly? I don't think so...

Case in point, shot number 5 on the first target could be--by virtue of its velocity--put with shots 6 and 7, and we could call the charge weight for shot number 6 the center of one node. Of course we'd have to slide shot 5 to the left, or shots 6 and 7 to the right to make this all work out. We could say that the wind moved shot 5 to the right. Or shots 6 and 7 left. Do we really know that?

Shots 18, 19, and 20 are in virtual lock-step as far as velocity goes. But look where shot 18 printed. Shots 19 and 20 are together--what happenend to 18? No one can truly know.

And one would like to move shot number 11 back to the right (maybe the wind again), and stack it in there between 10 and 12, because it looks like it belongs there. But wait a minute... shot 10 was 3686, and shot 12 was 3684... but shot 11 (with a charge weight in between shots 10 and 12 was about 65 fps SLOWER at 3617 fps. How could that be?

I'll tell you how it could be. Extreme spread variations will rear their heads at every point along the continuum. Variations in case neck tension will mess with the ES, when otherwise it might have been tight. You simply cannot allow the chronograph to steer your choice here. There are other examples I could cite, but that should suffice.

The target must be the final arbiter. Wide Extreme Spreads can and will totally obfuscate the results. With only one representative shot of each powder charge, how are we to know exactly why one shot tanks in the numbers?

Too, chronographs sometimes get it wrong. A little bit of unburned powder follows the bullet through the sky screens and a read error occurs.

That leaves us with only the target itself. But what do we have there? Did the wind move shot 11 out from between shot 10 and 12, or was it barrel whip? We cannot say for sure.

However... /ubbthreads/images/graemlins/smile.gif

If we could factor the wind out of the equation as much as possible--by shooting at 100 yards... and if we could test more than one shot of each charge weight, three perhaps... and if we could put those three shots of each charge weight on paper in a manner which would help to factor out a heating and fouling barrel, a tiring shooter, changing light conditions, etc... then we'd have OCW, and our results would be more intelligible.

I don't expect to convince some of you that OCW is by far the better way to go. I can probably blame myself for that, as I've been abrasive at times in my enthusiasm to share the idea.

But for those lurkers out there that are still wondering about the OCW method, and whether or not it offers the distinct advantages over the ladder method which I claim that it does--I hope I have made some sense here.

4kedHorn... I realize that you and Sean are trying to learn about the ladder test, and I would think that a dissenting point of view such as mine would be helpful when trying to gather all of the facts. You're a reasonable person, and I believe you'll agree with me there. If I've been rude, arrogant, or too sarcastic I do apologize for that... /ubbthreads/images/graemlins/frown.gif

Dan
 
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A little bit of unburned powder follows the bullet through the sky screens and a read error occurs.

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Man, how close are you putting that chono? If the powders not burned @ 10 ft you've got problems that no load developemnt is going to fix!!
 
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Thank you, 4kie. You saved me some typin'.

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Thank you for supporting me in my thoughts. You have no idea how many times I have written scathing replies knowing that they are unproductive then delete them in exchange for somthing that I hope will be taken as a courtious challenge to another reasonable members reply. I really like it here and I don't want to get the boot but at the same time a guy has to step up and say what is on his mind.

I hope that is the sort of typin' I saved you from. /ubbthreads/images/graemlins/wink.gif
 
Green thank you.

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I would think that a dissenting point of view such as mine would be helpful when trying to gather all of the facts.

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This last reply was a dissenting point of view. Still a bit of a hijack of the question but I'm not the hijack police and I know I do it all the time. None the less, it is at least something that can be discussed.

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If we could factor the wind out of the equation as much as possible--by shooting at 100 yards

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Or by graphing the relative vertical impact height of the ladder sequence perhaps? It has been my experience in learning to read ladder tests posted by others and now my own that plotting the shots on a graph has shown definate grouping patterns similar to the high and low groups shown on your bbl vibration diagram. The same goes for plotting velocities. There seem to be certain patterns that at the very least reveal a glitch in the increasing velocity string and often show and corespond to the impact patterns.

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Too, chronographs sometimes get it wrong. A little bit of unburned powder follows the bullet through the sky screens and a read error occurs.

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They more often get it right within a certian tolerance. And I'm going to have to say the powder thing is a bit of a stretch. Infact I know that the chrono I have been using has a delay in it so this dosen't happen. You can override this delay if you want to measure the cyclic rate of full auto fire but is an override on the auditory sensor and not the skyscreen start and stop sensors.

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But for those lurkers out there that are still wondering about the OCW method, and whether or not it offers the distinct advantages over the ladder method which I claim that it does--I hope I have made some sense here.

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And for those who, like me, are trying the ladder test for the first few times and are not getting the feedback as plainly as we might have expected and are doubting that you will be able to find the same benefits from this test that hundreds of benchrest competitors claim it offers-- I hope I have also made some sence and given you the encouragement to stick with your plan until you have the experience to know that you want to find another way (or not).

(Green, I hope you are still having fun. It is mostly about having fun.)
 
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