If a new rifle is only good for a minute of angle at best and one fires a ladder test at 400 yards, how does one know any bullet hole is at the top or the bottom of the rifle's group ?

Should one fire three or four of each amount of powder at 400 yards?

Ladder just help you find the node.

You then have to confirm with groups.

He's confused between a ladder test and the OCW method...

If you are at 400 you should see the progression. It can be useful to shoot up the ladder and then down for better data. 3 tenths between loads should do fine. You should see one or two groupings.

You run an experiment all of one time and expect conclusive results - yeah right . . .

Now you know why Ringman gets so frustrated.

MuskegMan,

There is a thread on http://www.longrangehunting.com/forums/ where a guy shows how to get to the correct load in about two dozen shots. He does a few shots to establish the best over all length and then does a ladder, one time, and he is finished with that load for that rifle.

How do you know it won't do better than 1 MOA ?

I'd test that theory by shooting different weights and seeing what groups best ...

Then I'd move it to 200-300 yards and shoot a ladder with that group, and it will tell you the node.

.. You could run the test twice and see if you get the same result...

Spotshooter,



It was a theoretical question. I was not referring to any particular rifle.

Sure thing, but how's it working out for you?

MuskegMan,



It seems to be working out for me.

The other day one of our .com friends suggested I get some Nosler Accubond 140 for my other 6.5mm rifle. I did and while I was at it also snagged some H1000. I fired one ladder test at 300 yards on a day when there was a varying breeze. Sometimes it was coming from the left and sometimes from the right. I fired eight shots. Even the highest loads didn't cause any bolt lift resistance, but I figured I was finished anyway since the velocity was 3278 feet per second. The "group" was 3 1/2" X 4 3/4". From top to bottom, shots numbers 1 - 5 were only 1 1/4" with #2 right in the middle. I chose that one and used it to establish over all length. Then I ran several groups with that over all length to discover what powder charged it likes. Using that one I started getting several groups at 3/4" or under and switched to checking different primers. Tomorrow I think I will finish my quest for the most preferred primer.

The frustrating rifle with the Christensen Arms barrel is no longer. I disassembled it and sold the parts; except for the Pierce titanium action. The guy changed his mind.

The ladder method reminds me of my 70 year old grandfather water witching to find where to dig my aunt's well in the 1950s.
My father did not believe in it.
My grandfather, aunt, and father are all dead, but people are still drinking the water from that well.
I don't believe in the ladder method, but when I am dead in 20 years there will still be people using it.

Feynman did not believe in Carl Sagan's climate change model.
In reaction Feynman made videos on scientific method.
Feynman has been dead for 30 years and people are still violating scientific method and believing in easy to make climate change.

I spent the day yesterday working with an 85 year old PhD who also told off Sagan at a symposium back in the 80s about the same topic.
I don't often get to be around people who understand scientific method. I spent most of my life supervising tests I wrote, trying to keep technicians from introducing out of control variables.

the Audette has worked very well for me very quickly in most of the guns I tried it in....YMMV.

Beats the hell out of loading a bunch of 3 or 5 shot groups for sure.

It worked well enough with an AR and a new barrel, to set a range record and beat David Tubb at 600 yards in our state match many years ago...

Rost, my aunt's well has been working well for 60 years. That does not disprove the notion that my grandfather's water witching was a pointless ritual.
Who could imagine that some accuracy rituals have no reproducible measurable effect? That is called the null hypothesis. It is rat poison for bad science.
https://en.wikipedia.org/wiki/Null_hypothesis

Clarkm,

Are you saying water witching does not work or does work? What would be a scientific test to prove or disprove it? If it works every time for a certain percentage of the population and not for the rest of the population, for those whom it consistently works does it fall into anecdotal, or an anomaly or are the others anecdotal or anomalies?

Scientific minds want to know.

Just stop right there with Ringman. You never need to say any more, regardless of topic.

I've gotten better or the same results, with much less work.

I don't care if you want to just punch holes anywhere looking for water though, its your money.

RE water witching, I never could, but I sure could locate all kinds of pipes in the ground using a pair of wires held in my hands... flat amazing that you can do some things but when they work, asking why or trying to disprove them, sure annoys the pig.

With the Audette Ladder, you must ID each bullet strike to know what you have. Otherwise, it's just chaos.

I keep a target at the bench, draw in and number each bullet strike as I view the target thru the spotting scope. I transfer the number sequence to the real target when done.

From that target, I look for a cluster or "node".

DF

I also have a target diagram drawn on my load notes and try to mark the hits. It gets hard when your shooting tests at 500+. I like to color my bullets and use about 4 different colors. Usually I end up with 2 of each color but it's easy to see which bullet holes are which color especially on white paper.

Yeah, that can be a real challenge, especially with a half MOA rifle. I've made several 4-wheeler trips to the target when the bullet holes were too close to sort out thru the spotting scope. 500 yds. would be better than 400 in that setting, would spread them out some. It takes a good scope to see small holes at 500.

DF

Call me ignorant, but I have no idea what a ladder test is. I will follow Ringman's link a read about it, hopefully I'll grasp it on the first read.

Google Audette test method or some such... for some reason we have to call it a ladder these days rather than giving credit to Creighton Audette for publishing the use of it, if not totally inventing it.

It's a fairly complex concept, but I like to explain it like this:

1) You note where the bullet hits the target.

2) If the other rounds hit below it, it's at the top of the group.

Now here's the tricky part:

3) And vice-versa.

smokepole,

How 'bout if five shots on a 400 yard target, each with one grain more than the previous shot, make a group 1" high and 2 5/8" wide? Which one is at the top of the node and the other at the bottom of the node?

You are truly a stupid SOB.

Firing 3 or 4 of each powder increment would be an OCW test rather than a ladder test.
You don't need to go to 400 yards for OCW, 100 yards works fine.

Choose one test or the other. If you don't know the difference, it's harder.

That's a tough one, but I like to explain it like this:

1) Find the node and designate the bullet holes that are included in it.

2) Find the bullet hole within the node that is above all the others. It's at the top of the node.

Now, here's where it get's tricky again:

3) And vice-versa.

PS, what I meant to say was, the whole question of which round is at the "top of the node" is irrelevant.

Is he talking about top of the node as in "the highest most bullet impact mark" rather than the top of the node "the highest charge weight impact relative to the cluster"?

I do believe he is...

This doesn't get much better than this...

If you fire five shots at 400 yards it takes five shots. If you fire five three shot groups at 100 yards it is fifteen shots. If you fire five four shot groups at 100 yards it is twenty shots. Tell me which one will find the best load the quickest with the least amount of wear on the barrel and wallet.

You're the one who has countless posts asking how to do load development.

I have no idea how many rounds or barrels you have wasted.

I would suggest you decide on one method and stick with it until you know what you're doing. Screwing up both methods doesn't seem to be getting you anywhere.

NVhntr,



Tell me how I screwed up either one so I don't do that again, please.

I prefer and use OCW and have confidence in the results I get with that method. Here is a link describing the procedure in detail.
OCW

Here is why I prefer OCW
OCW vs. Ladder

If you want to use a ladder test, Google Audette Ladder Test and follow the instructions.

Ringman, I don't know if you screwed up on your test, but when you ask this question, it shows that you don't understand the purpose of a ladder test:



Five shots with one inch of vertical at 400 is outstanding, they're all in the node, and it makes no difference which round hit highest on the target. Unless four of the shots were clustered even closer than 1" (1/4 MOA) and one "opened up" the group and began a trend of stringing vertically that was continued by the next shots in the sequence.

Which didn't happen.

Or it could be I want to see what someone will post.



I'll try to find the target.

I can't wait.

ah, a master baiter playing now...

Glad you have time to play with people....

Edge of my seat.




Dave

If there is 1" vertical spread at 400yd you need to do the ladder test at 800yd with those 5 shots... paint each bullet a different color and see which three charges have the least vertical spread.
Then load in 0.3 increments in that charge bracket and take it to 1200yd, then pick the 3 in between the closest cluster and load 0.1 increments and shoot at 1500yds.
pick the load in the middle of the best cluster, hope it works with the new barrel after burning the original one.
Or you could just load a bunch of bullets with the median charge of those 5 shots (if it is cluster of 5 not 4 and 1) and call it good.

Neither my rifles or optics are good enough to shoot that tight, so I dont know if it is me or the equipment that is lacking. Or my tongue in cheek misaligning the sight picture.

I find single charges in a ladder can lead to false results. I generally load 3 of each in a ladder and use a chrono since even good groups at shorter distances don't mean much to me with horrible numbers. That works fine at 600yds and in but I don't like to push much further than that with big spreads in MV.

Here is a load ladder shot with 3-shots each of 41.5gn, 42gn, 42.5gn, and 43gn of H4350 and 140gn ELD from a 6.5 Creed at 300yds. 42gn showed almost no vertical while higher charges did even though they landed in nearly the same spot. I then shot 3 groups of 5 at .010", .020", and .030" from the lands. 27-shots from start to finish and I have a load that is on it (.6MoA including the round that wandered right, ES of 11fps, and SD of 5fps) without chasing false leads from a single shot ladder.

Looks ready to go to me. But what do I know? I keep asking for help.

Easy. Examine the target after each shot and number each placement.

Sorry. Wrong question. How does one know if the bullet hole is at the top or the bottom of the node?

To partially quote a relatively famous person, "what difference does it make?"

As long as it's consistent, one will secure a high level of precision and accuracy if he dials it in.

To that question, not sure there is an answer.

DF

Doesn't make a damn bit of difference whether top or bottom....as long as the bullet goes where you want it!!

It would make more sense to shoot groups from the top of a Ladder that to shoot a ladder it's truly on of the stupidest things I have ever heard of.

I struggled with this question as well. As a result, I have begun to use a hybrid of the OCW and ladder methods. I load three of each charge and shoot them at the same POA at 500 yards. I then mark the center of each group. I compare the center of each group and where they cluster together from consecutive increases in charge is what I go with.

I have seen at the upper end of a node, a group where two are close together, putting two right in there with the lesser charges, but the third being way out. When that happens, I don't choose the charge with the flyer. So far I've not seen a charge with the flyer in the middle of what would otherwise be a good node, but only on the upper or lower end of a node.

So far, this method is working pretty well. I used it to find a couple of load that are grouping 2" or less at 500 yards in my 6.5x47 Lapua.

John

Hondo64d,

I have a new barrel getting threaded for a brake. When I get it I will give your system a try.