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Discussion Starter · #1 ·
I hope you dont mind re-hashing this. Could you please explain to me the Audettes ladder again. I dont think I comprehended it very well last time. Specifically WHAT is it you are looking for? Do you do this through your Chronograph? When you bump it a tenth of a grain at a time and you see a "group" is this an accuracy node? Or have I got it all screwed up in my pea-brain. Thanks in advance to a newbie. T.
 

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Audette, at your service...

I hope you dont mind re-hashing this. Could you please explain to me the Audettes ladder again. I dont think I comprehended it very well last time. Specifically WHAT is it you are looking for? Do you do this through your Chronograph? When you bump it a tenth of a grain at a time and you see a "group" is this an accuracy node? Or have I got it all screwed up in my pea-brain. Thanks in advance to a newbie. T.
Audette's concept: The idea is to load one or several series (7-10) of rounds separated by and incremental increase in powder charge, and then (after getting the scope on paper) firing the series on paper and looking for a tight grouping within the (vertical) series - all the while watching for pressure buildup. If a grouping is discovered, then use the Audette results as the basis for further experimentation.

Well, I tell ya... I think I have given the method a good workout, and this is what I've learned in order of importance, beginning at the top (and others can chime in here too):

  1. It is a dandy technique - if not to pinpoint a good load, it will point out bad loads w/ a minimum amount of rounds/time/expense. There are good loads, bad loads, and bad rifles... The Audette method will not make a good load out of a bad combination of load and rifle, and I mention this because I have struggled some with the ladder method until this seemingly simple lesson finally soaked into my thick skull!;) (More on this later)
  2. It's use is limited to initial or rough sorting (of potential loads) only i.e., further development of a potentially good load is done using more conventional 3-5 shot group tests using chronographs, etc, etc.
  3. Use small increases of powder between loads (I've 'bout settled on 1% as max incremental amount between test loads, e.g., .3 Gn difference for a charge weight of 30 grains).
  4. Charge weight accuracy is critical to the results. The more accurate, the better. I have found the powder throwers - even a Harrell - to be a major source of trouble in getting consistent results. It stands to reason: If the thrower is +/- .2+ grains, it is a bitch trying to load in .2 grain increments:mad: For that reason I weigh every charge carefully. There's an old rule that says accuracy of the measuring device should be .1 of the smallest significant amount being measured. (The Denver Instrument MXX-123 digital scales weighs down to .02 Gn. This one instrument made a huge difference in reducing the amount of variation - ambiguity - in the ladder results.)
  5. A good load will be foretold buy a narrow vertical string of impacts, with a tight 3-5 shot grouping. Not so good combinations seem to have more horizontal or scattering. The more horizontal element in the group, the greater the level of ambiguity and the less likely the load combo is going to work. If none of the traditionally good loads for that caliber work, it may well be something wrong with the rifle or the bedding or scope, etc.(this is written in blood, sweat, and tears, my friend!)
  6. The longer the range, the easier it is to interpret results. And, the better the loads/guns are, the shorter is the range necessary to determine a good load. Hu has had some luck using 100 yards, and for a bench class rifle I can see how that would be possible. But, for a new factory rifle or even a bench rifle, longer distances make for easier interpretation. I have 200m at my disposal which I often find to be a bit short. Most that support the Audette method seem to favor 300 yards as ideal - I wish I had that much at my disposal.
  7. The more powder/bullet combinations you try, the better the method works, and the quicker you can concentrate on a good load and forget trying to make a so-so load do what it is never going to do.

The Audette method is abstract. It requires the individual to be able to find direction from a scatter gram - too abstract for some to appreciate and is often criticized and dismissed out of hand.

To describe the concept, it is a like looking at a road map to find the "best" route between two points: With the Audette method one looks at the start point and the destination point and lets the eye find the more direct route(s). Using the traditional 3-5 shot group method is like being oblivious to anything but the start point and each individual highway, and having to explore each and every route individually until the destination is (sooner or later) arrived at.

More often than not I find it takes standing back and looking at several tests as a whole to see a trend and what the gun is trying to tell me. Put it this way...A narrow vertical string of rounds with 4 shots touching vs. a 10-shot "scatter gram" makes it easy to pick out which load is going to warrant further testing and which one to eliminate.

So, in summary...

I put all this "stuff" into my answer, because the method is so abstract. With all this info as background, it will be easier to understand that focusing on any one ladder test, and especially only a few shots from a single test is not likely to show you what you're looking for.

Initially, for those starting out it might be best to suggest one shoot only groups of ladder tests using different powders and bullet combinations. From those results as a whole, one can determine what is working and deserves more attention. As you become more familiar with interpreting the "tea leaves", you will be able to look at the results of a single ladder test/load combination and be able to determine if that load has promise or not. Where I and others fall into a trap is trying to make too much from any one test. IMO, the Audette method is best used as a preliminary sorting tool and left at that. Once a load shows promise, then go to the traditional 3-5 shot group series to sort out the truth.

Narrow, vertical strings with 3-5 shot clusters (or 4-5 shot clusters is better) is what you are looking for as a starting place for the next step of load development. The more horizontal scattering and randomness in the results, the less important any apparent "clustering" is. Good loads are going to have narrow tight ladders, and the more combination tried the better...I can't stress this enough.

HTH,

P.
 

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Discussion Starter · #3 ·
Thanks Paul.

That clears it up a LOT. So each ladder is considered a seperate test. So fire each combination to build a ladder then go on to the next combination for another ladder and so on. Then compare each ladder against each other? Do I have it squared away? Then when you see a cluster you do your traditional tweaking on that particular grouping. So this is particularly valuable on a brand new rifle or a switch to different components. This methodology might not be so useful in just trying out a new powder? Or do you run a ladder on the powder charge and look for a group within the ladder?
 

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Yep! You're on the right path...

That clears it up a LOT. So each ladder is considered a seperate test. So fire each combination to build a ladder then go on to the next combination for another ladder and so on. Then compare each ladder against each other? Do I have it squared away? Then when you see a cluster you do your traditional tweaking on that particular grouping.
Correct. ;)

Something I neglected to mention is the conditions when the test is being run need to be as "perfect" as possible. Differences in POI for .3 grains of powder in a 6BR can be subtle, and a switchy 10-15 mph wind will add a lot of horizontal elements that might not otherwise be there. On days where there is some wind, I tend to ignore horizontal stringing, in spite of using a half-dozen flags along the length of the range. (Did I mention wind flags?? Flags are very important to have in order optimize uniformity.)

So this is particularly valuable on a brand new rifle or a switch to different components. This methodology might not be so useful in just trying out a new powder? Or do you run a ladder on the powder charge and look for a group within the ladder?
It is especially useful with a new rifle - i.e., whenever starting from "scratch". However, I do skip the ladder test if I have reason to expect a certain load will likely work. It depends on how much information I have before testing.

For example: My 6-Dasher is cut with a reamer made by the same David Kiff (PTG) using the same specifications and drawings used to built the reamer used in James Phillips' 6-Dasher. So, as it turns out...I can skip the ladder test and go directly to powder and bullet recommendations, starting with 3-5 shot group tests. (However, before I decided I could skip the ladder test, I did run a ladder on one of James' load suggestions. The results were almost identical to his findings; powder and seating depth wise. After that, I skipped further ladder testing and go directly to group tests, i.e., fine tuning.)

So, I've brought you to the edge of my experience - the crystal ball is growning dark:rolleyes: All I can suggest is stick with it and don't be tempted to switch to traditional group testing until you have narrowed down a group of loads. A pitfall I got into early on was once finding what looked like a good ladder, I would then stop doing more ladders on more components, choosing to try to "turn silver into gold" (later discovering better combinations months, or years and many $$$ later that I would have known about sooner had I continued with more component and ladder tests). The more times you use the ladder, the better you will be at "reading the tea leaves".;) On thing Allan (Lucky Shooter) Weldy is playing with is shooting a series of horizontal dots in sequence. Doing the ladder test this way has the advantage of breaking out each individual impact which might otherwise be lost when multiple rounds go thru the same hole.

Lots of ways to skin a cat. What makes developing loads so interesting/frustrating (at the same time) is the number of variables that are interacting. So, the trick is to eliminate as many variables as possible. In other words, pay close attention to details.

I find that a good load is one that is not only accurate, but relatively forgiving. However, before arriving at the load plateau, often small powder charge variations, or seating depth variations, or neck tension variations, etc. will have a greater impact on POI than a particular powder and bullet will have, once the "sweet spot" is found. So, during development, it is especially important to be careful with measurements - especially powder charge weights (one of the reasons I broke down and bought the DI MXX-123 digital scales - specifically to refine ladder testing).

Well, the 10% part is done; the instructional part. Now for the 90% part...The hands-on part!

Good luck! Glad to answer more questions, if I can.

P.
 
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