Ladder Test

YoteslayerWA

YoteslayerWA

Well-known member
Anyone ever have a ladder test that doesn't ladder?

I started load development today for a new bullet in my .308 win. I am working on a load using 168 eld match and Varget. I looked in the Hornady book to find the suggested min and max charge. I came up a few grains from minimum because the range is from 32.6 up to 44 grains.

I started at 38.5 gr and worked up to the max of 44 in half grain increments. All bullets were seated to the same depth and all other variables were the same. When I went out and shot the rounds I did have much for vertical displacement. All the shots were within a 3 inch window.

Is this something normal or has anyone else experienced this? Should I just be happy with my findings and work toward the upper end to get the highest velocity? I have ran these tests for other rifles and found a much larger gap in the vertical displacement and was able to clearly pick out some good nodes to work off of.
 
I always load 3 rounds with each powder load and go off of group size. I could see where it would be leas components doing your way, but also be a little harder like your case to tell which charge is best. I am NO expert so take it for what it is worth sir.
 
Not too unusual @ 100 IME. This is a 100 yd. ladder w/a 243 WSSM.

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Creighton Audette's recommendation was 300 yards IIRC. The longer range gives you more spread and is easier to evaluate. Since I have access only to 100 yd. range, I rely on chrono readings more than POI when the spread is not real obvious.

Regards,
hm
 
Like Panyote, I too prefer a 3 shot group (on sporter rifles, 5 shot on varmint/Precision rifles) to determine load development. Im not a velocity hunter so I dont worry too much about 100 fps difference.

I have found that doing it this way at 100 yards, a lot of time bullet impact is in the same place so if I were to do the same with a ladder test, I would just have a big mess of holes.

Its worth noting that at 100 yards, the velocities wont be far enough apart to give much vertical dispersion. I have always heard of guys who do the ladder tests doing it at 200 or 300 yards.

This was a recent group with a varmint rifle. 3 shots to preserve the ever elusive Nosler BT. I load 5 rds to foul the barrel with the selected powder. Let it cool. Then shoot 3 to 5 shot groups starting at min charge and working up in half grain increments. Min charge here was 23 grs. These loads chrono right at 3000 fps from a 26" tube.
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Sometimes you get lucky and a load shoots that was picked right from the book.
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Point being that I never liked the idea of a ladder load for this reason. Most of the ranges around here are 100 yards and the places I have to shoot that are more than that are very windy and not ideal for a setup. If it were me, I would try 5, 6, 7, and 8 with 3 shot groups and see what happens.
 
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I always thought that ladder test had to be done way way out there, at least past 300 yds for the bullets to even have a chance to climb the ladder? I believe the guy who started it always did it at 600 yds and further.
 
You need to list your velocity, that will determine your nodes. I did a ladder test with my 22 Creed a few weeks ago and all 12 rounds were in 3/4 of an inch (at 100M). Chart your velocity increments and see what node is the best. Many times your best node in velocity will not be your best groups, that's when you adjust seating depth.
You can see my chart below, the first 4 shots are from 40 to 40.6 going up in incs of .2, so I was 40@3181, 40.2@3179, 40.4@3179, and 40.6@3185, that's only a difference of 6fps in 4 shots with different charges in each.
So I went with 40.3 which is dead nuts in the middle of this node, group opened up to at least an inch when I sent 3 rounds at 40.3. BUT velocity stayed dead nuts, so I increased OAL and put the 80.5's into the lands, and they all went in the same hole after that.
I look at the ladder test to find your velocity node, so your variation is minimized at longer ranges. At 100 to even 400 it's not going to matter, when you hit 500 to 600+ it's starts to. Your one hole group at 100 doesn't mean jack if your velocity varies by 20fps when you need to reach out and touch something.

 
Minimal vertical node than find correct seating depth. The longer the distance the more important minimizing vertical stringing, then you just need to make the correct wind call.
 
Skinny,

I appreciate you taking the time for the write up. I will definitely put the info to work and in the memory bank. It’s always good to have guys like yourself on the forums willing to share their wealth of knowledge.
 
Originally Posted By: YoteslayerWASkinny,

I appreciate you taking the time for the write up. I will definitely put the info to work and in the memory bank. It’s always good to have guys like yourself on the forums willing to share their wealth of knowledge.

Thanks buddy, I don't know much more than the other fellas, I just like getting into details and, enjoy learning from hands on as well. If I can share some of my experiences to help others out, GREAT!
 
Skinny,
I also appreciate your opinion's. Its funny how you can read something in a little different way and a light bulb goes off....
I wish that light bulb would go off more often!
 


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