Shot a ladder test. Now what?

The ladder test , I have found it to be very effective to find sweet spots in barrel harmonics, or , lack there of.

Use it, please don't discount it.It is especially good when you are looking for mid to long range data.

Here is a set of photos showing a few results , I will explain them as I go...

This is a ladder test on what I later discovered to be a poor barrel, the benefit is I didn't go chasing 5 shot groups, that would have been a lot of wasted powder, the spread of these shots is a very clear indicator of something not right, I could not duplicate any results resulting in scrapping the barrel.It does show some clusters but again, could not be duplicated.




This is a ladder test with the new barrel ,this shows a major improvement in over all cluster and small clusters , excellent starting point.Same distance as other ladder test.

This one is one powder..



This is another...



Even though the top powder has a phenomenal 3 shot group I chose to pursue the second powder as the overall group to me was less sporadic, which to me was more important due to the fact that it would be less effected by changes(temp, environmental, clean/dirty) , in other words to me it was a more harmonious powder to use.

After this I moved out to 500 as I really felt I had the combination I required so I moved on and tested some groups, as I felt I had a node in the higher end and no pressure signs I upped my charge weight on the top end and tested...

At this distance you can really tell where the rubber meets the road, starts to determine where the accuracy really lies as close up may look alright but start stretching it out, those little differences really become apparent.



I then did some three shot groups in smaller increments, almost duplicated the group size...



This was a good example to me of it working correctly, using minimal components.

IMO recording the charge weight next to the hole makes interpretation a tad easier to find your nodes and go back and forth between targets.A chronograph isn't necessary but it does help.

Like others have stated though, what is your end game? Extreme range accuracy or hunting?It can be used for both just depends how refined you need to go.

Learn to read and feel the groups, take note of the shots you feel you may have pulled , this helps . my 95gr target shows such a shot which I discounted then confirmed later with one more test.I will stretch out to 1,000 and may or may not play with seating depth as I feel the accuracy achieved now is what I want.

Confirmation with duplication will be your guide.

Don't let others bring you down, I still consider myself new at this, first try is always first try , first date didn't go so smooth for most of us either!

There are lots of people here willing to help , send PM's if you feel like not asking in a public forum.

One thing I forgot to add, just something I do, I load 5 extra of my lowest charge to get on target just in-case I am running a whole new setup/rig, terrible feeling to miss the target with your first charge and only have one! :(:redface:
 
Last edited:
curseyou said:
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.
Click to expand...

Unfortunately the photo given doesn't provide anything for scale except the bullet holes themselves, but it looks to me like this 10-shot group at 300m measures about 130mm extreme spread, that's a 1.5 MOA group. The group formed by loads 4-5-6-7-8-9 looks to be sub-MOA. This is with cartridges with varied powder charges! This is not poor shooting, nor is it a substandard rig. If nothing else I say this ladder test suggests you are going to be able to throw together almost any load in this range and expect very accurate ammunition.
 
Since you did not state where you started, I checked Sierra and believe you started with their recommended accuracy load, IMR4831.

Accuracy Load: IMR-4831/ 71.6grs. 3000fps/ 3598ft. lbs.
Hunting Load: IMR-7828/ 76.8grs. 3100fps/ 3841ft. lbs.

By going up another two grains of IMR4831 you can get to the 3100 fps listed for the hunting load.
Run your test again was suggested.
Since IMR7828 was the "hunting load" it is another reasonable place to start.
If you have a Chronograph that is also a benefit as you may see unexplained variables
 
StevieK said:
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
Click to expand...

Do pretty much the same thing. Rifles 3-5 shots at 100m and pistols a full mag shooting at 10m to start.
 
Seeker what you didn't mention is the minimum charge and maximum charge weight of the powder you used. And where you started with the amounts.
For example my 270 can use 35 to 55 grains of powder and for a ladder test I started with 45 grains and the next was 45.5, 46, 46.5 and so on right up to 55 grains. I found a node at 49- 51 grains then narrowed it right down to 50.1 for my best results. Your ladder test is a bit confusing. I recommend you clean your barrel with a copper remover and then fire a couple of fouling shots and try the test over at 200 yards. 300 win mag like to be clean for load development. A ladder test usually starts at the bottom of an 8.5X11 page and works its way up the page as the load gets hotter.
What twist of barrel? New brass or fire formed brass? Use a lead sled or some gun mounting devise for the 300 ladder test.
 
BattleRife said:
Unfortunately the photo given doesn't provide anything for scale except the bullet holes themselves, but it looks to me like this 10-shot group at 300m measures about 130mm extreme spread, that's a 1.5 MOA group. The group formed by loads 4-5-6-7-8-9 looks to be sub-MOA. This is with cartridges with varied powder charges! This is not poor shooting, nor is it a substandard rig. If nothing else I say this ladder test suggests you are going to be able to throw together almost any load in this range and expect very accurate ammunition.
Click to expand...

Looking at op's photo, the ratio of horizontal variation to vertical suggests to me that I can't trust the variation in vertical is actually due to barrel harmonics causing clustering, or just variability in gun/shooter/ammo which is what a ladder test is for. This is a low confidence result. Having a sub moa cluster, in a more or less circular pattern tells me something is wrong. Could be the shooter. Could be the ammo, could be the gear.

If you don't see a vertical pattern it ain't a ladder test.
 
You won't get much of a vertical pattern if you are in tune, please look at my previous post showing the two powder results.

If you are approaching 2" x 2" cluster at 2 to 300 yards what do expect for a vertical with varying charge weights?


curseyou said:
Looking at op's photo, the ratio of horizontal variation to vertical suggests to me that I can't trust the variation in vertical is actually due to barrel harmonics causing clustering, or just variability in gun/shooter/ammo which is what a ladder test is for. This is a low confidence result. Having a sub moa cluster, in a more or less circular pattern tells me something is wrong. Could be the shooter. Could be the ammo, could be the gear.

If you don't see a vertical pattern it ain't a ladder test.
Click to expand...
 
Kelly Timoffee said:
You won't get much of a vertical pattern if you are in tune, please look at my previous post showing the two powder results.

If you are approaching 2" x 2" cluster at 2 to 300 yards what do expect for a vertical with varying charge weights?
Click to expand...

Depends on the variation in your charge loads and how meticulous you are with reloading. An initial ladder test usually has charge weights from a starting load to max load in .5 or .3 gr hops for most mid caliber cartridges. You should see a clear vertical pattern at 300 yards. One you dial into one or two of the nodes you find, you are right you won't see much vertical, but then it is not really a ladder test, as now you are shooting for groups.

Think of it this way, if your spread in the horizontal plane is 5", and you are trying to interpret vertical changes of the ladder test of 1.5", your margin of error is too high to get much meaning. If you were to repeat the test, would you get the same results?
 
curseyou said:
Depends on the variation in your charge loads and how meticulous you are with reloading. An initial ladder test usually has charge weights from a starting load to max load in .5 or .3 gr hops for most mid caliber cartridges. You should see a clear vertical pattern at 300 yards. One you dial into one or two of the nodes you find, you are right you won't see much vertical, but then it is not really a ladder test, as now you are shooting for groups.

Think of it this way, if your spread in the horizontal plane is 5", and you are trying to interpret vertical changes of the ladder test of 1.5", your margin of error is too high to get much meaning. If you were to repeat the test, would you get the same results?
Click to expand...

Alright , so how would you interpret these two ladder tests?

This one sure shows some nice vertical with clustering.



This one , obviously shooting for a group? No?

 
The ole box test , or some variation.



Kind of similar but not.

The Typical box test is to start at your zero , adjust left X so many clicks , adjust down same amount, adjust right same amount , adjust up same amount and if you like left again to return to zero.Forming your "box"

Mine was a bit different, I wanted to see if mine returned to my zero after each shot.



radmacks said:
I always thought the ladder test was for testing how a scope tracks. Guess I learn something new everyday.
Click to expand...
 
curseyou said:
Depends on the variation in your charge loads and how meticulous you are with reloading. An initial ladder test usually has charge weights from a starting load to max load in .5 or .3 gr hops for most mid caliber cartridges. You should see a clear vertical pattern at 300 yards. One you dial into one or two of the nodes you find, you are right you won't see much vertical, but then it is not really a ladder test, as now you are shooting for groups.
Click to expand...

You don't always get nice vertical patterns with ladder tests.
This one I shot a few weeks ago. Not a "optimum" result, even at 500m, but the node is quite clear (10-16)

20151215_202242_zpsxcqdzqrv.jpg


Here is a better one at 300yds. Still some strange movement, but the node is also clear (11-15)

DSC00583_zpse7d1ac01.jpg


Also depends on the rifle. I had a 6BR that shot beautiful ladders every time. My 308 on the other hand was very prone to "shotgun" ladders. I'd have to do multiple tests to find the sweet spot, but I was able to do it.

One last point. You won't nail down your exact load off of one ladder test. I typically do two ladders, one coarse to find the rough nodes, then one with finer intervals to fine tune it. THEN I shoot some groups at long range to confirm.
 
I think that some believe that a barrel only moves up and down during the whipping process , IMO it does like flat "s" or squiggly type pattern kind of.

To me it is shown in group testing as they move on two axis not just one.

I have had more exaggerated results but this is all I have a photo of, not only a tighenting of the group but vertical and horizontal movement.

SO a ladder test to me having horizontal deviation is part of the process, especially going from below minimum up to your maximum charge.A lot can take place in the spread, which a ladder shows much easier and with less bullets wasted.



Sorry for getting off topic.
 
^^^^ That is a good example of what you are looking for in an OCW test. If you find the average point of impact of those three groups, you'll see it moves to the right. In an OCW, you are looking for the node where the point of impact of the groups don't move with increasing powder charge. As Kelly mentioned, this has more to do with barrel harmonics than muzzle velocity.
 
All of this is very interesting and I do understand the idea behind it...the only thing for ME is that the point is to find and accurate load without using as many resources, yet for my hunting load needs I can always find a good load by just starting shooting groups and trying about 5 or 6 different charges.
Would trying a ladder test at 100 yds be helpful in the slightest or is it pointless at that close a range?
 
100yds is pretty pointless. Only way you'd see a vertical spread is if the powder charge intervals were huge, and in which case you'd probably not see the clusters.
I suppose you could use a chronograph, but you would really have to trust its readings.
 
Well 5 or 6 different charges, times 5 or 6 shots. Then repeat a group or two for final selection, plus sight in @ 200 for typical hunting rifle zero. Let says 50 shots for easy math.

Now you could load 10 loads, finer increments , then maybe 5 more to duplicate a confirm a node, and even do a 5 shot group or two and then sight in. Maybe 30 shots

Do all this at 200 and you should be good to go for any hunting situation and distance.

100 is too close for a ladder test on most chamberings.

Start doing your testing and sight in at 200, even on your ladder to start off, gives you that kick in the bum to be that much more accurate and consistent.

StevieK said:
All of this is very interesting and I do understand the idea behind it...the only thing for ME is that the point is to find and accurate load without using as many resources, yet for my hunting load needs I can always find a good load by just starting shooting groups and trying about 5 or 6 different charges.
Would trying a ladder test at 100 yds be helpful in the slightest or is it pointless at that close a range?
Click to expand...
 
You must log in or register to reply here.
Back
Top Bottom