After the ladder test.

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BJung

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Here is my question. I tend to do a ladder test than an OCR test to save on components. Yet, I use open sights and don't trust my aim as much as if I used a scope. So, if you use a ladder test, what do you do? Do you Do you take the load that is in between to printed holes with horizontal lines close to one another? This works well with a scope where I line up my scope cross hairs to the lines on the target. Or, do you take the printed holes that's closest to each other, with consecutive load, and take an average? I figure that if I replicated the same two loads, then theoretically the same load will go through the same hole. That said, the average of those two printed holes that would be 1/2" from each other would print somewhere between those two loads and close POI. Would you follow up with a COL, three shot ladder test within these two different load parameters? OR, would you load say a 5 shot testload of say 0.2gr apart from one load to the next and choose the load that groups best? Again, I'm using open sights.
 
I am not sure what you mean by OCR test. What rifle and cartridge are you loading for? When I did ladder tests, I shot my series using the same aiming point and keeping track of the POI of each round on my notebook. Once I found a node, I would load up some 3 shot test groups spanning the loads that formed the node. If those held up, I would pick the middle charge weight and reload and shoot a 5 shot group or two, just to verify and see how the load does.
 
I am not sure what you mean by OCR test. What rifle and cartridge are you loading for? When I did ladder tests, I shot my series using the same aiming point and keeping track of the POI of each round on my notebook. Once I found a node, I would load up some 3 shot test groups spanning the loads that formed the node. If those held up, I would pick the middle charge weight and reload and shoot a 5 shot group or two, just to verify and see how the load does.
. I am now loading for a T99 Arisaka and I am using the standard iron sights. An OCR test is a ladder test like your second set of ladder tests where you load 3 rounds. Thanks for sharing. I might use your method.
 
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What’re you shooting? Paper for points, steel for fun, beasts for food? Are you looking for something to impress the neighbors or just put a little meat in the smoker?
Currently I'm shooting at paper. The 174 FMJBT is for fun long-range shooting. The 150 Barnes is for hunting. My goal is to have an accuracy load for my guns and guns my family owns so if I or my nephews get the chance to hunt, there will be ammo for it.
 
For me, it's extra work doing both a ladder and then an OCW. Anymore, an OCW test is all I do, but with a scoped rifle. My aging eyes can't take me past 100 yds with iron sights well enough for an OCW test anymore. :(


I do this:
Or, do you take the printed holes that's closest to each other, with consecutive load, and take an average? I f
 
For me, it's extra work doing both a ladder and then an OCW. Anymore, an OCW test is all I do, but with a scoped rifle. My aging eyes can't take me past 100 yds with iron sights well enough for an OCW test anymore. :(

A scope helps a lot. If my iron sights are off by an inch because I can't produce a consistent sight picture, I'm often concerned that my accuracy load tests will be affected. This especially applies to my 200 yard + shots.


I do this:
 
Currently I'm shooting at paper. The 174 FMJBT is for fun long-range shooting. The 150 Barnes is for hunting. My goal is to have an accuracy load for my guns and guns my family owns so if I or my nephews get the chance to hunt, there will be ammo for it.
If I'm using iron sights. I shoot a set of 5 shot groups at 100. Then I retest the ones I think might be worth retesting.
I also try to find the size target that closely matches my front sight at 100 yards. It helps with precision.
I don't care about velocity variation with iron sight loads. Just POI because I'm not shooting it far enough to matter.
 
If I'm using iron sights. I shoot a set of 5 shot groups at 100. Then I retest the ones I think might be worth retesting.
I also try to find the size target that closely matches my front sight at 100 yards. It helps with precision.
I don't care about velocity variation with iron sight loads. Just POI because I'm not shooting it far enough to matter.

Are you spacing each of your set of groups 10% apart or .3%- .5% apart?
 
Are you spacing each of your set of groups 10% apart or .3%- .5% apart?
I usually divide the charge range by 10 shots.
This is usually about .3-.4 grains in 308 based cases.
.2 gr in 5.56.
If I get close to a load. But think it could be better. I'll divide it up smaller where I think the load will be.
 
I hope I know what you’re asking.

I use a scope for my long range shooting so I hope this applies.

When I work up a ladder, it’s just to give me ideas.

Say if my 22-250 shoots tight at 37.7 grains, tighter at 38.0 grains, back to the 37.7 group at 38.3 grains, I’ll load the 38.0 grain load 10Xs. I’ll shoot 2 groups. If they are what I was hoping for, I’ll load some more, get the gun dialed at 200, then move back to 300, 400, 500.

sometimes 200 is a struggle and I’ll go back to the drawing board. Other times the gun puts 3 bullets in the same hole. I smile as I get it zeroed, dead nuts at 200. Smile bigger at 300.
 
Ladder tests, made famous by Creighton Audette, are a long range load development method. Group size (in replicant tests) isn’t as critical as vertical displacement between adjacent charge weights.

Here’s an example I analyzed for someone several years ago, fired in triplicate. Each line represents the center of its respective group.

52F5542C-A9DF-458D-AC12-4CB78B2EBBE9.jpeg

In this particular test - we see from #1 the center drops a long ways to #2, then up a long ways to #3, then back down a long ways to #4, up quite a bit again to #5, but then #5 and #6 are very close together, before diverging again up to #7, and up up again to #8….

This suggests a node is somewhere around #5 and #6, so a guy should test again in that area with tighter charge increments (if statistically feasible for the dispensing/weighing method), to better define the edges of the node.
 
Sounds like OP and I are headed up the same path and with same destination in mind. Except OP either is or is not loading for a Type 99 Arisaka WW II era bolt action military rifle using iron sights. If that is the case, I'd be happy with just about anything that safely goes BANG.

I'm working with a rifle that for a variety of reasons, hasn't been able to do much better than 2 MOA at 100 yards. Still in the process of sorting out why that is, but if I was getting that with OP's rifle with open sights, I'd be all grins and giggles and doing back flips.

And as for the load ladders, my simple understanding of those now is they are an a series of incrementally increased powder charges in otherwise identical loads. They are shot at enough distance, such that differences in velocity from incremental powder charges creates a vertical impact spread. A function of bullet drop tied to velocity. The impact of each round has to be known and identified. The optimal charge is found when two or more shots in the increment print on same horizontal plane, such that a change in powder amount does not affect velocity much. That is an accuracy node. That also assumes the guy on the trigger is good enough shot such that the spread is in the load, and not the shooter.

And thanks to a link we were given that explains all this, the guy doing the explaining also included one more helpful tidbit. As per that guy, the incremental powder charge increase was to be 0.6% of the max load. So increment is not 0.2 or 0.3 or even 0.5 grains. It depends on case size and amount of powder charge. Load ladder I have now and am waiting for chance to fire I used and arbitrary 0.2 grain increment. Could have been 0.3 grains to cover more ground with 10 round ladder. If that is true, most of the calibers I'm loading for.......with max powder charges in range of 45 to 60 grains, 0.3 grain increments is a good all around number.
 
For me, it's extra work doing both a ladder and then an OCW. Anymore, an OCW test is all I do, but with a scoped rifle. My aging eyes can't take me past 100 yds with iron sights well enough for an OCW test anymore. :(

They are both incremental charge testing.
 
A lot of these test point of aim to be basically perfect and dispersion is a factor of loading. Unfortunately only volume of data can be used to average and remove shooter input. Step one is to only shoot at a range that your in control of point of aim and not guessing or good enough. Palma guys shoot iron sights to (infinity and beyond - buzz lightyear) load development depends on reducing shooter error and environmental factors so is normally begun at 100 yards, with optics. When I develop with my leverguns iron peeps I use a target with a Bullseye slightly larger than my front post at range to give me what I believe a reasonable point of aim. You may find the black on a target fits the bill well, but I don't like black as my pins are black. A paper plate works well.
 
For me, it's extra work doing both a ladder and then an OCW.

Functionally, OCW and Ladder tests are the same thing. It’s like writing reminders on post-it notes instead of a notepad or vice versa, but the notes are the same either way.

ETA:

The photo I shared above was actually a compilation of shots OCW test, superimposed onto the same point of aim as if they’d been fired as an Audette ladder.

In the original pictures of the OCW test, we can see the yellow line flattens between 5 & 6.

D687E74C-B1C2-4985-878E-AD42AEE28AA8.jpeg


Were this fired at a single POA, as an Audette test, those group centers would create these elevation lines - again, showing a node between loads 5 & 6.
5DAFF735-5417-4985-906C-4AAFB17FFF8F.jpeg

Just a matter of choosing how you want to see the targets, and deciding whether you want to deal with the logistics of keeping track of which hole is which (bullet marking) or logistics of hanging more targets.
 
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Functionally, OCW and Ladder tests are the same thing. It’s like writing reminders on post-it notes instead of a notepad or vice versa, but the notes are the same either way.
There should be a Dam navy troubleshooting flowchart for the load development section in every reloading manual. There should be built in offramps for every level of reloading from make it go bang to 1kyd br.
 
I look at my targets and find the one where all the holes touch or nearly touch eash other .
I have written the load data on each target so I know which is what .
Cloverleaf groups win the day ... scattered patterens get discarded .
Gary
 
A few years ago I used the single shot ladders and felt they where easy to interpret when in reality they are both arriving at the same conclusion.

Where is the load stable and performing well ?
It’s in the overlap ..
 

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I like your visual approach to the OCW data interpretation, Varminterror.
Functionally, OCW and Ladder tests are the same thing. It’s like writing reminders on post-it notes instead of a notepad or vice versa, but the notes are the same either way.

ETA:

The photo I shared above was actually a compilation of shots OCW test, superimposed onto the same point of aim as if they’d been fired as an Audette ladder.

In the original pictures of the OCW test, we can see the yellow line flattens between 5 & 6.

View attachment 1117942


Were this fired at a single POA, as an Audette test, those group centers would create these elevation lines - again, showing a node between loads 5 & 6.
View attachment 1117943

Just a matter of choosing how you want to see the targets, and deciding whether you want to deal with the logistics of keeping track of which hole is which (bullet marking) or logistics of hanging more targets.
 
I typically load in 1% increments, rounded up. If I have only maximum data I drop 10-12 percent and go up from there. If I have minimum I start there. For pistols I use 0.2 grain increments because my scale only measures 0.1 grain increments and I think that’s too small to worry about when I start mad producing loads. For 223 it’s 0.3 grain increments and for 30-30 and 308 it’s 0.4 or 0.5 grain increments. I then choose the best and go with it until it proves me wrong. I generally assume the real group size will be about 25%-50% bigger. I also have a minimum requirement. The lowest charge that meets the minimum accuracy is my load.

For example I just tested CFE 223 and 69 grain RMR 223 bullets in an iron sighted M16 A4gery. The first test charge shot the best. That’s what I’ll load until that load shows it’s worse than my minimum. My target accuracy is 1.5” at 100 yards. I have other loads that will regularly meet that from this rifle. The lowest charge group was less than that (~1.1”). Minimum charge below accuracy goal is my new load. I am not concerned with wringing every last foot per second out of a load. There are always bigger calibers.

I spent a lot of time developing a method and target combo I could trust with iron sights on this rifle. I use a 12” target with a careful 6 o’clock hold at 100 yards. I also use the small aperture and a chevron front post like the Washington monument. I also put a 2 stage target trigger in the rifle and over the coarse of testing 8 different loads I spent a lot of time behind this rifle. Target configuration helps me a lot when testing with or setting up iron sights.
 
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