Ladder Tests

[Ballistic64]

I agree with GG,the OCW,ladder or any variation is not complete without a chrono.Either test by itself is not going to indicate that the load which shows promise is a good long range load but used in conjuction with a chrono you can get a much better idea if it shows long range promise.If your working on a long range load and it shows promise with the ladder-ocw test but the chrono is showing high es,you know you have some more work ahead of you.I know a high es somewhat contradicts a ladder-ocw test but it happens.The main reason I use the ocw method is because there is more data on the target(s) from repeated loads than the single shot on the conventional ladder.Im not trying to tell you this is the way you should do it,just giving you ideas from what Ive done.You'll eventually draw your own conclusions with your testing methods.Good luck and good shooting.

 

[BountyHunter]

All the discussion on wind in ladder tests goes back to one of my main points on developing serious LR accuracy loads and the ladder tests.

DO NOT DO IT IN THE WIND!

Do all serious testing for LR in "no wind" conditions. They can normally be found early mornings and late evenings, but not always.

Are you there to test accurate loads or are you there to test your wind reading ability?

Another point, highly accurate rifles at 100 yards will shoot one hole most of the time if a decent load. Very hard to tell what shot did what inside one hole.

That is another reason to go to 200-400 yards in no wind conditions.

BH

 

[Jimm]

So very

All the discussion on wind in ladder tests goes back to one of my main points on developing serious long range accuracy loads and the ladder tests.

DO NOT DO IT IN THE WIND!

Do all serious testing for long range in "no wind" conditions. They can normally be found early mornings and late evenings, but not always.

Are you there to test accurate loads or are you there to test your wind reading ability?

Another point, highly accurate rifles at 100 yards will shoot one hole most of the time if a decent load. Very hard to tell what shot did what inside one hole.

That is another reason to go to 200-400 yards in no wind conditions.

BH

True . A properly conducted ladder test will give the operator a ton of data to consider and will quickly point to the potential of the bullet / powder combo being tested .

However , the most important aspects of the test can be discovered / examined regardless of the wind . Velocity and vertical to put it succintly .

I know a fellow that routinely conducts his ladder tests in the windy environs of central Oklahoma . Yet he just as routinely benefits from the results . Perhaps he will have the time to chime in here . If so we will all benefit .

When conducting a ladder test with a person new to the method it is invariable that each shot of the test produces exclamations on their part such as " what the heck is that shot doing way over there " . To truly benefit from the results of the test you must wait till all data is in hand and then reach informed decisionsd by a careful interpretation of said data .

Targets , velocities and load info will work together to tell you what to do next .As in all things , experience will provide more and greater insight interpreting the info .

As Bountyhunter pointed out the distance the test is conducted at will help improve the understanding of what is happening . Even so if you only have 200 yds to work with the method will still work . It may take a little longer( more experience ) to be able to interpret accurately but it will happen .

Jim B.

 

[AJ Peacock]

I like ladder tests, but don't view them as a 'be all end all test'. I shoot them over a chronograph at 200yds and take into account the velocities and impacts as a whole. I even do them in low switchy wind conditions and then just look at the vertical component of the shot to shot spread (this takes wind reading entirely out of the equation).

At the end of a ladder test, I absolutely know a couple things.

1) I know the approximate velocity of the entire range of loadings for those powder/bullet/primer/seating depth combinations. I can use this later to select a velocity range to work up a load.
2) I know the upper range for that powder/bullet/primer/seating depth. I know that I'm not going to get much more velocity than this, as I stop the ladder when I either see pressure signs, or start seeing velocities near the upper range shown in reloading books for top end pressures. I then know my upper load range for this combo.

I MAY suspect a couple other things

1) I MIGHT have a cluster of shots that MAY represent a 'node'. I'll normally load 10-15 rounds in the center of each of these 'nodes', just to see if one of them is REALLY an optimum load combo for this rifle.
2) If I'm using a rifle that I'm not familiar with, at the end of a ladder test I'll usually know about what kind of accuracy to expect from that rifle. If the entire ladder ihas 3 shot clusters less than 1 MOA or so, I know I've got a shooter. If the entire ladder looks more like a shotgun pattern that a rifle target, I know I have some serious work to do. I'll also typically have a feeling whether this particular barrel likes the hotter loads or milder loads.

AJ

 

[squirrelduster]

I am new to ladder tests

I am new to ladder tests.
Two months ago I had no idea what a ladder test was so I did some research here and on the 6mmbr.com forum.
I have a 300 win mag that I have been having a terrible time getting it to shoot. My groups were in the 1 1/4 to 1 1/2 range, pretty horrible.
I ran my first ladder test using IMR4831 and a Berger 190gr VLD bullet. It seemed my results liked a 72.5 grain load. I was getting better groups varying the powder charge than when I was loading three at a time.
I was able to load up several sets of three and adjust the oal length .005 in more for each set. I shot a group of .741 outside spread in the wind and rain a couple days ago. I know that is probably not up to snuff with most of you guys but the group is half the size than when I started so there must be some validity to the ladder method. I know I still have more work to do but if I can get some decent weather maybe the groups can be shrunk some more.
I don't have access to a Chronograph so I will need to check groups at long range to make sure I have a decent load.

 

[Jimm]

So , in a nutshell

Squirrel , ( sorry , couldn't resist ) the ladder test has worked good for you , yes ? Keep on using it for different bullet powder combos as well as different rifles anmd you will be a ladder test fan .

The best load for my 300 winnie ended up being 74 grs. of RL 22 under a 190 smk, around 3080 or so velocity . .750 3 shot groups at 300 .

If you can get your hands on a copy of Creighton Audettes book " It aint necessarily so " you will find some interesting and informative reading.

Jim B.

 

[jeff 300]

Thanks for the link. That was a good read.

I agree!!!!!!!!!!!!!!!!!!!!!

 

[boomtube]

"My only comment would be to shoot no less than 300 yds,"

Would you elaborate, why aren't the results at 200, or even 100 yards worth considering?

I don't shoot past 200 yard hunting nor 300 for varmits. Prefer to get closer, as a hunter more than a shooter I guess. Anyway, I start development with a ladder test at 100, when there is no significant wind to confuse things, and go to a modified OCW test when the nulls are found in the ladder test.

Can't understand why initial testing needs be done at much greater ranges, but do understand that not all 100 yard loads shoot well at longer ranges. ????

 

[ss7mm]

Would you elaborate, why aren't the results at 200, or even 100 yards worth considering?

I don't shoot past 200 yard hunting nor 300 for varmits. Prefer to get closer, as a hunter more than a shooter I guess. Anyway, I start development with a ladder test at 100, when there is no significant wind to confuse things, and go to a modified OCW test when the nulls are found in the ladder test.

Can't understand why initial testing needs be done at much greater ranges, but do understand that not all 100 yard loads shoot well at longer ranges. ????

If you're shooting a factory gun with typical factory accuracy, you may be able to do it at 200 yards. With a custom gun, and the resulting accuracy, typically anything less than 300 yards only results in a lot of holes very close together and usually you will have shots going into areas where the target is all torn up.

Shoot it at 300 yards, or more, and it's easier to see what's going on, easier to mark the shots and easier to see where the nodes are. It's kind of like the difference in watching tv on a 12" screen vs a 42" plasma screen.

I shot a ladder test once at 300 yards and also loaded up some extra duplicates and also shot it at 100 yards. The result at 100 yards was just one big ragged hole in the target. The one shot at 300 had the shots spread out enough to track them, mark them and it also made it easier when done to interpret the results of the test.

 

[Jimm]

what Dick said

If you're shooting a factory gun with typical factory accuracy, you may be able to do it at 200 yards. With a custom gun, and the resulting accuracy, typically anything less than 300 yards only results in a lot of holes very close together and usually you will have shots going into areas where the target is all torn up.

Shoot it at 300 yards, or more, and it's easier to see what's going on, easier to mark the shots and easier to see where the nodes are. It's kind of like the difference in watching tv on a 12" screen vs a 42" plasma screen.

I shot a ladder test once at 300 yards and also loaded up some extra duplicates and also shot it at 100 yards. The result at 100 yards was just one big ragged hole in the target. The one shot at 300 had the shots spread out enough to track them, mark them and it also made it easier when done to interpret the results of the test.

Times 10 !! Dick , as usual you put it so well . Every time I see a fellow knee deep in brass at the range trying to dope a load for his new rifle I explain the " ladder test " to them .

Time and again the results they get makes them happier campers . Sure there are other methods out there . Always has been more than one way to skin a cat . But ................. the ladder test is so dang simple , results so reliable , ....................and it doesnt confuse as easily as some other methods .

Jim B.

 

[.280Rem]

No ladder tests, no OCW for me. I load up the bullet I want to shoot, and try 2-3 different powders. One will usually show to be more accurate. I work up to the max by watching the chronograph. I seat everyting touching the lands. If bullet wont show the ability to group (a recognizable shot pattern of some decent size) with any of my chosen 3-4 powders, then I pick another bullet. It works for me.

 

[284STW]

I agree that the farther ANY load testing can be shot the better. That being said you can have success with 100yd ladders as well. I just got done working a load on a friends mod 700 sporter in 7 RUM. This rifle isn't designed to be a tack driver with that whippy factory bbl to begin with. After bedding the recoil lug I loaded 12 rounds at 1/2 grain increments from 96 to 101.5 w/ us 869 behind a 168 berger. The 96.5 to 98gr loads grouped well, the group opened quite a bit, then the 100 and 100.5 loads went right into the 96.5 to 98gr holes. I then found a best group at 100.3 grains shooting at 3220 avg. Moved out to 400M and shot a three shot group of 2.8" ctc. Good enough for a hunting rifle with minimal work done belonging to someone who will probably never take game farther than 400 anyway. I had repeatable hits with this load out to 600M on a mule deer sized target.

 

[boomtube]

"anything less than 300 yards only results in a lot of holes very close together"

Okay, I understand. You are understandably seeking an "expanded scale". But, that confusion can be eliminated quite simply at 100 yards using my modified latter tests. Basically, I only fire a single round at a single target so there can be no cluster holes to swallow bullets at all.

When I load for a ladder test, I number each round with a Sharpie, which resists smudging very well on clean brass. If I get clumsy and spill them, they are easily restored to order. Then I number a series of small targets with the same numbers as the cases and shoot at them in turn. A notepad keeps track of the charge, or seating depth, and the velocity of each round is entered as I fire them.

When the shot series is complete, I take another target and make a composite of all the fired shots on it. I lay the fired targets over it in turn, marking the hole and numbering each as I go. If things start getting too cluttered, I simply make another composit target to keep things distinct and clean.

There is no confusion, no bullets are lost in the cluster and it's all done at 100 yards. And a couple of my old factory rifles, an original 22-250/Browning-Sako and a Rem 40xb/6mm International produce consistant groups under .5" during my ladder tests.

 

[AJ Peacock]

I also use multiple targets, in pretty much the same way. But I don't transcribe them onto a single target. I measure the vertical component of each shot and graph the vertical difference between it and the shot before and after it (My spreadsheet takes the measured differences and computes the MOA differences and graphs them). The graph shows me where the nodes are. On a second graph, I graph the velocity differences against the shots before and after. When I get a node on the vertical distribution graph that is in the same spot as the velocity graph, I'm a happy camper. Here is an example from an excel spreadsheet.

A very accurate load was found around 57.5gr from this ladder test.

Hope this made sense.
AJ