Ladder Testing for Long Range Shooters

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Maple57

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So I was reading an article where the ladder test efforts were designed a little differently than what I assume most would follow.

Instead of picking a powder charge that clustered at one end of the barrel oscillation cycle or the other, which would result in the tightest 100 yard group, they deliberately selected the powder charge where the increased charge resulted in a lower POI than the next lesser powder charge.

While this would not result in the tightest 100 yard group, the thinking is that given an imperfect velocity spread, sending a slow bullet off on a higher trajectory and a fast bullet off on a lower trajectory will balance themselves out down range and result in a more consistent vertical dispersion at extended ranges.

Have you guys tried this?

What are your thoughts?

Do you think a load developed in this manner could be relied upon to remain inside the velocity spread window over typical temperature variations we get during a given season?
 
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Yes, that's called positive compensation. Issue is, it will only appear at a specific range depending on the velocity and bullet.
For example:
At 600 yards, the slower/higher bullets and the faster/lower bullets arrive at the same elevation.
At 1000 yards, the slower/higher bullets will be below the faster/lower bullets.

You will be better off finding a consistent velocity node so all the rounds have the same MV.
 
I read that the positive compensation was the driving force behind the mods done to competition SMLE No. 1's and No. 4's, back in the day, for the Full Bore competitions. You could not use your ammo - had to use what was supplied for that shoot, but it had to meet standard - average 2440 fps, +/- 40 fps maximum variation. You couldn't "tune" the ammo, so the rifle bedding was "tuned" to that ammo specification - slower speeds launched higher, faster launched less high, all came together for the 800, 900 and 1,000 yard targets. Placement of bedding "packing" and stock up pressures were of great significance. First half of 20th century technology accomplished this.
 
I think there's something to the velocity idea. I've been OCW testing at 200-400 yards for quite a while but after following Scott Satterlee and his methods, I think it may be worth a try

Check this out:
h ttps://www.65guys.com/10-round-load-development-ladder-test/
 
It's all interesting theory, but in my experience, I've found loads that do not reside at the end of an oscillation cycle feel like they will loosen my teeth under recoil, while the loads leaving at the ends of an oscillation cycle are more accurate in general and go off with a certain deadness to the feel under recoil.

It's hard to describe but in this regard I have often felt that I could probably "feel" and accurate load under recoil while shooting in the dark, but I'm really just sensing the vibration.

Possibly simply leaning toward the load that starts the downward POI shift might have some inherent benefit I suppose, but I doubt it could be relied upon.

So my focus has always been to reduce my ES to negligible levels rather than grasp at such work arounds that to me seem only effective under a narrow range of temperature.
 
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At 100yds, watching ES might actually lead you down the wrong path but you can prove that yourself easily enough.

POI has never related to accuracy for me.... small groups are where they are on the target... I adjust my scope when done. But then I have run pretty much all contours and lengths over the years.

My tuning at 200 to 300yds with the right components have proven robust for all year round F class competition and PRS competition... mind you I don't enjoy shooting near ZERO and avoid winter matches... but I do shoot approaching 40C. An operating range of 30 to 35C is a wide enough for me.

YMMV

Jerry
 
I've bounced back and fourth between 100 and 300 yard load development over the years but found 300 yard attempts full of induced environmental variables that contaminate the purity of my results. Except for the rare occasion where I've been out shooting just as the fog clears.

What I've found comfort in is tight groups at 100 yards with a low single digit velocity spread.

If it's not accurate at 100 its not likely accurate farther out.

I suppose with respect to this whole positive compensation thing, maybe I could swing the load a little in that direction perhaps as a sort of insurance policy.
 
I found 100 yards ok to start load development ( OCW style), but then it becomes difficult until you move back. 300 is nice, especially for seating depth. (OSD)
Then your powder charge will be in a node, and your seating depth will be in a node as well.
 
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