New load ladder, what does this mean?

[Dirt farmer]

I'm trying to use the Hornady ELD Match .308, 168 grain bullet in my 30-06. Cannot find an accurate load above 55 grains of IMR4350. I'd like to be shooting around 60 grains of powder. I loaded one each at in 0.1 grain increments from 59.1 gr through 60.0 gr. I've read about "shooting ladders" and "finding an accuracy node". I'm a pretty good shooter and was using a bench and rest at 100 yards when I shot the below target. I walked out and marked each shot to let my barrel cool between shots.
I cannot interpret the "ladder".
What does this shooting mean, anything? Help please!!!

 

[Bandit67]

Back to the drawing board. Lol.
Seriously I think you should load up at least 3 rounds of each and shoot them at different targets so you can get a better idea how they group. Based on that pic maybe you can eliminate the first 3 shots and start your test at 59.4.

 

[BigBore45]

That is a long bullet and needs a slower twist rate. So I guess once you speed it up with more powder it is over stabilizing and causing bad accuracy.

 

[Dirt farmer]

Back to the drawing board. Lol.
Seriously I think you should load up at least 3 rounds of each and shoot them at different targets so you can get a better idea how they group. Based on that pic maybe you can eliminate the first 3 shots and start your test at 59.4.

Ya, thought so. Thanks for your response.
As much as I didn't want separate deer load and an elk load for my '06 but I think that's where I am with these bullets. I'll just shoot them with 55 grains of powder as I can get a 3/4" group with that load, and I'll use them for deer.
I get 1" groups with Hornady 165 gr SP Interlock bullets with 60.0 gr of IMR4350 powder which I use for elk. I just don't like the Interlock "smashed lead tips" so I was looking at the ELD plastic tipped bullets.

 

[horsey300]

Ya, thought so. Thanks for your response.
As much as I didn't want separate deer load and an elk load for my '06 but I think that's where I am with these bullets. I'll just shoot them with 55 grains of powder as I can get a 3/4" group with that load, and I'll use them for deer.
I get 1" groups with Hornady 165 gr SP Interlock bullets with 60.0 gr of IMR4350 powder which I use for elk. I just don't like the Interlock "smashed lead tips" so I was looking at the ELD plastic tipped bullets.

So run the 165 gameking hollow point, 165 interbond, 165 grand slam, 165 accubond, or 165 a-frame, all should work for you, all have plastic, hollow, or protected points. The eldm is a match bullet, not a hunter, but as for your workup, I'd run 3-5 rds each, take the best one, and see if tweaking coal helps, if not, different powder, the eldm has a different profile from your Interlock so the jump is different.

 

[Laphroaig]

First off, I think the 1 shot per charge ladder test (the Creighton Audette version) is designed to test a much wider range of powder weights. Typically, you increase by 0.3 grains per load in an -06 size cartridge. So for a 20 round test, you are testing a 5.7 grain range of powder. I still sometimes do this kind of ladder when starting from scratch. Sometimes it tells you something, like an obvious node or two, sometimes not so much. I still always learn something and keep on doing it. Its beneficial if you chrony each shot.

Your results are interesting to me. That is a pretty significant and constant increase in elevation between shots from 59.1 to 59.5 grains. Like I said, 0.3 is a typical ladder amount, its striking that the elevation increases that much for 0.1. Things start jumping around some from 59.6 to 60.0, not really an accuracy node IMO. My conclusion is you probably won't find an accurate load in that powder range for that powder/bullet combination. But it sounds like you already know that.

Did you chrony those loads? I'm asking because 59.0 is over max for 2 sources I checked, 165 bullets and IMR4350.

 

[Iroquois]

Back to the drawing board. Lol.
Seriously I think you should load up at least 3 rounds of each and shoot them at different targets so you can get a better idea how they group. Based on that pic maybe you can eliminate the first 3 shots and start your test at 59.4.

I agree. One round is not enough to show deviation. 3 to 5 rounds will yield much better results. As Bandit67 states 59.4 seems the logical place to start.

 

[Varminterror]

Unless you charged with an analytical balance - aka lab scale - you didn’t test anything of value. Even a balance beam typically will be +/-0.1grn, at best 0.05, so each of your increments may have been identical the one you thought was below or above it...

No less than 0.3grn in a cartridge with 40+ gen target weights.

I also shoot 3 shot groups, round robin, and shoot at 300yrds to separate my vertical a bit. You can’t tell if you have a high shot out of a group beside a low shot of a group, or actual vertical dispersion.

You don’t show any groups at all, so if all of this is the same size as a 10shot group of one charge weight, then I’d reiterate, nothing meaningful here.

If pretended this target were meaningful, then I’d play with seating depth between 59.4 and 60.0, and focus around 59.6. But again - your 59.6 might really be a 59.7 or 59.5, and I can’t be sure how much is gross precision vs. vertical dispersion.

Shoot at 300, 3 targets, round robin, 3 rounds each load. Superimpose the results onto one target. Ignore the horizontal, focus on the vertical dispersion.

Your node is somewhere between 59.4 and 60.0. Your POI is climbing fast from 59.1 to 59.4, then you gain very little 59.4-60.0, and you’re bobbing up and down in that range. That is where you want to be.

 

[wrench459]

Ya, thought so. Thanks for your response.
As much as I didn't want separate deer load and an elk load for my '06 but I think that's where I am with these bullets. I'll just shoot them with 55 grains of powder as I can get a 3/4" group with that load, and I'll use them for deer.
I get 1" groups with Hornady 165 gr SP Interlock bullets with 60.0 gr of IMR4350 powder which I use for elk. I just don't like the

I would have a debriefing meeting with the meat that you shot.
And ask them which MOA did you prefer?

 

[someguy2800]

The term “shooting a ladder load” as I have always used it means you load 5 of each charge weight of increasing charges, like the rungs of a ladder and shoot them to find the most accurate.

What is interesting about the way you did it is that there is a large difference in point of impact from shot to shot from 59.1 to 59.4, and from 59.6 to 60.0. The shots from 59.4 to 59.6 are relatively close together. It looks like they are at about the top of the barrels harmonic swing. Interesting. Or it could be random dispersion.

 

[Muddydogs]

If you can't put each and every shot right where it's supposed to go then the ladder test means nothing and the average a few times a year shooter isn't going to put each and every shot where it's supposed to go. A pulled shot or two basically throws the whole ladder test off.

No offense to the OP but he stated a couple posts down from the first post that he has a load that shoots 3/4 of an inch and another at 1 inch well I've only had a few loads in 30 years of load development that were over an inch group at 100 yards. If I want a good load for a rifle i'm looking for that under 1/2" group or basically all the bullet holes touching each other. I can get a 1/2 to 1 inch group just by picking a load out of the book and loading it. No i'm not a crack shot that's why I like to shoot 5 shot groups when working up a load and if 3 shots are touching each other I investigate that loading further as I know i'm going to pull at least one if not two of the 5 shots. From the first whispers of this new ladder test method I have called bull on it for the average shooter.

If I was you OP I would load up a few 5 shot groups around your 60 grain target charge and just see how they group, you already know the pressure is fine.

 

[Varminterror]

The term “shooting a ladder load” as I have always used it means you load 5 of each charge weight of increasing charges, like the rungs of a ladder and shoot them to find the most accurate.

What you described is not a ladder test.

For the Creighton Audette ladder test, one round of each progressively heavier charge weight at the same POA. Multiple shots of each charge can be taken at the same POA, but the shots still should be fired round robin. If shooting groups, then the centroids of the groups can be used to get a better idea of vertical climb between charges. I prefer to shoot one shot of each charge, and then repeat 3-5 times on 3-5 targets.

The idea is to find charge weight ranges where the vertical dispersion between neighboring weights is smallest. These are the nodes. Do some reading on positive compensation for further study of what a “node” really means. I tend to call it my “forgiveness window” or “charge weight envelope,” as it represents a span of weights where I can have pretty significant variability in my charge weights without revealing variability on the target.

What is interesting about the way you did it is that there is a large difference in point of impact from shot to shot from 59.1 to 59.4, and from 59.6 to 60.0. The shots from 59.4 to 59.6 are relatively close together. It looks like they are at about the top of the barrels harmonic swing. Interesting. Or it could be random dispersion.

This observation of clusters is the point in doing the Ladder Test (same essential theory as flat velocity span and OCW). As you noted, in this shooter’s target, there’s a pretty small vertical dispersion at the top of his charge weights, so as I mentioned above, his node is somewhere above 59.4. He has a very small deviation among neighbors in that span.

I called out the problem with how this shooter performed the test - there’s not enough spread between charge weights, not a long enough range to reveal enough vertical dispersion (vs. group size), and there aren’t any replications of the test. But if we pretend this is meaningful, somewhere between 59.4 and 60.0 is where I would do further exploration and development.