Thread: 440m ladder test

Howdy
Matey and I have been working on some 6.5cm/143eldx/2209 reloads.
This was shot at 445 meters-

Our next step is to bracket the loads of shots 3,4 and 5.
At what stage would you adjust your seating depth?

Um, I don't understand your target...

Were these all shot at the same point of aim, and the lines represent vertical climb ?

Originally Posted by ebf

Um, I don't understand your target...

Were these all shot at the same point of aim, and the lines represent vertical climb ?

Yes,but the lines just lead to where I wrote the charge and velocity.

riiiight, and why are you choosing 3,4,5 to focus on ?

also, what chrony did you use ?

single shots don't tell you much. how do you know you did not shank any of the shots and affect where the point of impact is ?

I guess I am asking if your primary focus for analyzing this is velocity or drop ?

if it is speed I would be focusing on 5,6,7,8

6 and 7 would be my pick I always do a ladder at 100 as you are mainly looking for a flat spot in vol.
If no pressure I would go higher my Creedmoor used to group best around 2770 with the 143 the 2 powders I used were the same the best groups were around the same speed.
For a ladder I load as you have and shoot at 100 sometimes I don't even shoot on a target I look for the flat spot or node and check for pressure then load 5 of each 3 loads around that flat spot then I'll shoot them on a 100 m target.


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Why would 3 be above 4 and 9 be above 10. I don’t think anything can be derived from this data?

Watched a video recently by Ryan Furman on Long Range Only about this type of load development (which I'm going to try) and his experience showed that the testing needs to be done at a minimum of 600m and preferably 800-1000m if you have a very accurate rifle. And 2 shots per charge weight.

You need to be this far away to get meaningful results and to be able to isolate vertical nodes properly

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Originally Posted by The Claw

Watched a video recently by Ryan Furman on Long Range Only about this type of load development (which I'm going to try) and his experience showed that the testing needs to be done at a minimum of 600m and preferably 800-1000m if you have a very accurate rifle. And 2 shots per charge weight.

You need to be this far away to get meaningful results and to be able to isolate vertical nodes properly

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I have read a fair bit Ryan has written and he is a clued up guy read alot of info he has put up about the 30 nosler. To test that far the conditions would have to be pretty perfect. Not saying it cant be done. I think 440yards has given a good indication there. two shots per charge is definatley idea though.

Originally Posted by Tim Dicko

I have read a fair bit Ryan has written and he is a clued up guy read alot of info he has put up about the 30 nosler. To test that far the conditions would have to be pretty perfect. Not saying it cant be done. I think 440yards has given a good indication there. two shots per charge is definatley idea though.

He reckons the results are still accurate with some wind. As long as you accurately place your shots and call any pulled shots before you see the target. It's vertical nodes that you are looking for and can discount horizontal due to wind. He also doesn't use a chrony during this testing phase as he reckons tight vertical is more important than flat velocity nodes

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Originally Posted by The Claw

He reckons the results are still accurate with some wind. As long as you accurately place your shots and call any pulled shots before you see the target. It's vertical nodes that you are looking for and can discount horizontal due to wind. He also doesn't use a chrony during this testing phase as he reckons tight vertical is more important than flat velocity nodes

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Thats interesting. Its a combination of things It depends on your methodology. i remember watching a video Dave Tubb was saying he does a ladder load at 200 yards quite offen by the sounds of it. https://www.youtube.com/watch?v=qP4PBnX6cZ8 11minutes in.

shots four and five are close for velocity and that. you could try load 40.7, 40.9, and 41.1.(fill in the gaps) if its a real flat spot for velocity and vertical spread go with a charge in the middle.

I would look at 41.3 but would also extend the ladder into the 42+ range so long as there are no high pressure signs.

If you discount shot no.1, 9 bullets from cartridges loaded with a 1.8 grain different charge weight went into 4.5”.
Bullets 3,4 and 5 went into 2.25”.I think thats good shooting at 440m from a factory B14.We are loading for accuracy not speed,its a hunter.
We will repeat the ladder with 6 from 40.6 to 41gn and report back.

Originally Posted by marky123

If you discount shot no.1, 9 bullets from cartridges loaded with a 1.8 grain different charge weight went into 4.5”.
Bullets 3,4 and 5 went into 2.25”.I think thats good shooting at 440m from a factory B14.We are loading for accuracy not speed,its a hunter.
We will repeat the ladder with 6 from 40.6 to 41gn and report back.

Ok, so you are pretty much focusing on "group size". Although as John pointed out above, groups of 1 kinda mean zip.

I would suggest you look at the speeds. Assuming of course you have a reliable and repeatable chrony.

Shots 5,6,7,8 are all within single digit ES from each other. It looks like a likely node in this ladder. Having said that, I would much rather look at SDs for 5 shot groups, the more data you put in the better the quality of the info you get out...

If (and it is a big IF), that is a node, then I would look at choosing a load in the middle, and playing with different seating depths. Shoot at least groups of 5. Do it at 100m and make sure the wind is not affecting group size.

Originally Posted by ebf

Ok, so you are pretty much focusing on "group size". Although as John pointed out above, groups of 1 kinda mean zip.

I would suggest you look at the speeds. Assuming of course you have a reliable and repeatable chrony.

Shots 5,6,7,8 are all within single digit ES from each other. It looks like a likely node in this ladder. Having said that, I would much rather look at SDs for 5 shot groups, the more data you put in the better the quality of the info you get out...

If (and it is a big IF), that is a node, then I would look at choosing a load in the middle, and playing with different seating depths. Shoot at least groups of 5. Do it at 100m and make sure the wind is not affecting group size.

As far as I understand,a ladder test is the relationship between POI and velocity.If unsuitable powder charges are used then they are nowhere near their next or previous.If it is,then they are closer together,hence 3,4 and 5 are suitable charge weights in this instance.Further testing with those charge weights will prove or disprove that.Happy to be proved wrong.