Shot a ladder test. Now what?

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Seeker2

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Started developing a new load today. I have always like the idea of doing a ladder test for load development, but never had a range to shoot at which was longer than 100yrds.

Here is a picture. Shot at 300M. Load is for 300 Win Mag, 180r Sierra BT, IMR 4831, in .5 gr increments. Not really sure where to go from here, i had figured that it would be a little more obvious where to continue development. I would appreciate any input.

I adjusted my scope a little more than necessary for the first shot, which hit quite high on the target, so I have drawn in roughly where it should have hit.

 
I must not understand ladder tests. I usually develop the best loads for my rifle by shooting at least 5 shot groups, letting the rifle cool, then going on to the next increment, and another 5 shot group, or more, then on to the next. I couldn't tell anything from what you have done but perhaps the experts can school us both.
 
I believe the idea is to see which range of powders group together (say shots 6,7,8 as an example) to narrow down the range of powder weights you go on to do full groups with.

I'm a bit skeptical though. I feel like one shot doesn't tell you much, and your results would easily change from things like one bad shot or a random gust of wind.
 
I'll stick with the OCW thanks.

What you have there shows me nothing at all. Anyone who thinks that they see something in the pic is also able to read chicken bones to predict your future.
 
ugh I had similar results, I said screw it! And made up 5 rounds in 1% increments of powder, and just shot those. Went from there on, costs more in powder and bullets but much easier to quantitate the results.
 
I believe the theory is, load up a number of shells with slight increases in powder charge. Shoot them at a minimum distance of 200 yards and see how they group. As the charge increases, wherever the shots start to get close to each other represents an accuracy node for your barrel- so you load up 5 of each and see how they group. The idea being you have to shoot less to develop a load. I seem to remember reading that the vertical grouping is more important than the horizontal, since wind can be a factor.

But I am a complete novice with this and may have my method off. If nothing works, I'll go back to the good old fashioned way you described, Chas59.
 
Your picture does not give even the slightest bit of information. Is each numbered shot a different load? Or did you shoot 3-5 shots with each load and then switch to another?

Typically for my ladder tests I load up from a mid range load to max, 5 rounds each. I shoot at least a 3 shot group with each. Sometimes I will skip a grouping of the lower powder charge and just shoot one to make sure there are no pressure signs. But you have to shoot a cold barrel grouping with each load to know which is accurate. Single shots with each load only prove to show if there are pressure signs with your load
 
when I do a ladder, I shoot 5, let the barrel cool , make the scope adjustments, then shoot 5 again- if you don't get a decent group somewhere on the paper, DECREASE your yardage and start over- get a DECENT group at whatever yardage and then start over and go from there until your groups increase in size, then start monkeying with the powder charge- and a .5 grain increment is silly until you get near the "sweet spot" - ise a .1- and if you're using a progressive, you might very well have that much variance anyway unless you dribble every charge
i also believe you have load development and sighting in confused- sighting in is to ESTABLISH the group, at a given yardage- i don't use meters- load development is to "sweeten " that group or to see where it groups at a given yardage- ie my old savage 99 in 308 Winchester shoots bang on at 250 using 180 grain bullets, off a bench, with the scope set at 9, and no wind- and does 11/2 -1 inch groups all day long- that's 44 grains of 748ovedr a ww mag primer- now you take that same load and dial it back to 300-325 and those groups open to 3 inches or more- same deal for 100 -200 yards,- in other words that rifle has a sweet spot right at 250-267 where mpbr is- but the REASON i can tell you that is LOAD DEVELOPMENT- that's what works for me in MY rifle- I've done ladders at those other ranges and with other powders and that is where i came out
 
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I don't see this single shot method really saving that much time and loadings...as has been stated previously if you have one bad shot with a load it throws off the whole test. And the 300 WM is an easy one to pull a shot. Although your powder charges are increasing your POI goes up and down all over the place. Although it won't always hold true you should roughly step up the "ladder" with each powder increase. This leads me to believe that the shooting accuracy may have affected it...not criticizing at all, could happen to anyone myself above all else. In the end you loaded 10 rounds to try and save the testing yet you've gained no Intel at the end and will have to load groupings from square one again.
 
Seeker2 said:
I believe the theory is, load up a number of shells with slight increases in powder charge. Shoot them at a minimum distance of 200 yards and see how they group. As the charge increases, wherever the shots start to get close to each other represents an accuracy node for your barrel- so you load up 5 of each and see how they group. The idea being you have to shoot less to develop a load. I seem to remember reading that the vertical grouping is more important than the horizontal, since wind can be a factor.
Click to expand...

With a ladder test, you are not strictly looking for an accuracy node. That has more to do with barrel harmonics, and a OCW test at 100yds would be better.
A ladder is supposed to give you velocity nodes. Points where increasing powder charges results in slim to no change in muzzle velocity, which means minimal vertical dispersion at long range. 300yds/meters is considered the minimum range for a ladder test, and even then you can get poor results like the OP. Longer range is always better, assuming you can still spot your holes.
 
you really won't determine anything with one shot. when I do a ladder test, I load 3 rounds with an identical charge, and work up in increments of .3 grain. when the groups tighten up I work up and down in .1 grain, and I load 5 rounds. I also clean the barrel before running the 5 shot groups. once a final load is established, the barrel gets a cleaning, and a final run of 3, 5 shot groups just to make sure. tedious, but it pays dividends. my 2 cents, and please feel free to post and make improvements with my technique.
 
This ladder test is a dud. No offence intended but you might not be skilled enough yet for such a test, or perhaps the gear is not up to snuff. Seriously consider a chromite rear bag. That will eliminate so much user error it is scary. Ensure you do the ladder on a calm day. I see too much horizontal variation, which is why I think there may be user, gear induced error. A good ladder test should be largely vertical. Ensure you have a quality scope and mounts and there are correctly mounted. Ensure your action is correctly attached to your stock. Ensure you are using a good consistent cheek weld, and that you are adjusting for parralax correctly. Also ensure you are using your best shooting technique and skip the coffee before the test.
 
Oh boy..... Not many of you seem to understand what a ladder test is & what it should show you. First of all, determine what you really want to do with your rifle. If you don't intend to ever go beyond 300 yards with any real precision requirement, go ahead & shoot a bunch of three or five round groups at 100 & skip the ladder.

What you want a ladder to show you is pretty much what Suther expressed - you want a range of charge weights printing close to the same vertical point on your target at a distance effective enough to differentiate between velocity changes. Consistent velocity is what equates to repeatable precision at long distance (at least of the controllable variables).

Testing at 300 yards is alright; I have done mine out to 500 with faster calibres. Impacts printing left or right can largely be ignored, as you're looking for vertical dispersion in a ladder test. If you look at shots 5 through 9, you'll see that they all successively printed into a "group" closer to each other than any of the others did. Shots 1 & 2 were likely fouling / warming shots, 3rd rose from where 1 & 2 probably should have been from a warm, fouled bore, 4th rose, 5th rose a bit but started a string of shots that 'settled down' in terms of vertical placement. 5 through 9 circled & then shot 10 carried off on its merry little way trying to find the next node.

This should show you a node where a small range of charges will display very similar velocities. Take this range of charges & break them down finer - shoot another ladder if you wish or shoot groups. You will most likely end up shooting groups, though. Most do. When you refine like this, you will most often find that the best load comes somewhere in the middle of the range which has another benefit - environmental stability (for lack of better description). What I mean is, when you load to the middle of the node, the resulting ammunition is more tolerant of changes in temperature. You've all read the stories of guys who had a fantastic load in -5 temps but when he shot it again the following July, he blew primers. He may have been at the top end of a hot node in the first place & with the increase in temperature, the resulting increase in pressure put it over the top.

The shooter's ability is definitely a variable. The OP shows enough skill to garner good information from this test.

And Shooter---/; I'll show you chicken bones alright. Bring your tissue box next time we're out.

Rooster
 
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Another thing I should mention is shooting ladders in triplicate. I like to shoot my first string from lowest to highest charges and dialed to impact 3 or 4 inches to the left of POA. Second string gets shot highest to lowest, dialled to your zero. Third string is shot lowest to highest, dialed 3 or 4 inches right.

This method shows me inconsistencies in my shooting and adds data for interpretation.

Rooster
 
I would shoot it again and see if you get similar results, or, as mentioned, do two similar side by side at the longest distance you can.
more data = more answers.
I see two possible areas to focus on with your first target. I would repeat and run with it, or change a component based on results.
 
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