Ladder test?

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pyscodog

Active member
Just curious how many people here use this way of finding a load for their rifles. I have never used it and find it hard, from what I have read, to figure out if its a waste of time or not. From what I read, some say yay, some say nay. What are your thoughts? I'm going to try it with my 17 Hornet just for the heck of it. What will it hurt?
 
I use the ladder method for all load development. I'm looking for the nodes within the loading range where the velocity (and usually POI) varies the least as powder charge increased. Often you will find more than one node in the string. By loading near center of an accurate node, you can usually eliminate the need to weigh powder charges.

Here is an interesting article regarding Creighton Audett's Ladder Method of Load Development.

Regards,
hm
 
I usually start with a short ladder in .5 grn increments. When I find something that looks promising I will adjust up or down in.25 increments. Then if I find something that I like I start to play with seating depth. There is no right or wrong way. Just find a method you like and go for it.
 
The problem I've read about is that it's not very repeatable. In other words, if you repeat the test more than once, you'll likely get a different result each time.
 
I have used them for a long time, and they do work. They will not, however, tell you much of anything at 100 yards. 250 is a good starting place, but you need to be able to shoot at least MOA at that range to really get good data. I'm sure you can do it!

You will see a distinct horizontal line of 3-5 powder charges. Load those again, and verify on another day. Then just pick a charge in the MIDDLE and use that for load development.

I betcha 90% of misses by GOOD shooters are high and low, and this has a lot to do with it. Solve the problem now.

There are many loads that shoot well at 100 yards. There are about 20-30% of them (educated guess) that can hold that accuracy at longer range.
 
I want to do this on my 17 Hornet. Not a super long range bullet. Whats a good distance to test? I'm thinking 150yds maybe.
 
Couple of questions for the group on this subject. If you change lots of powder do you have to repeat the whole process? Also does anyone know whether the ammo companies go through this process and if not what do they do to produce accurate ammo.
As for what range to use for the 17 Hornet test I think 150 would be good.
Thanks
 
Quote:Couple of questions for the group on this subject. If you change lots of powder do you have to repeat the whole process?

That's a really good question.

I never have, and have gone through a lot of different lots of H450, H4895 and IMR 4350 over the years. I have never experienced significant difference in performance or POI from lot to lot, but always cut back a few tenths and work back up when changing lots as a precautionary measure.

Could the nodes shift from one lot to the next? Sure could, but never noticed it affecting scores.

Regards,
hm
 
you want your bullets to hit in a horizontal line... not spread out up and down. The ladder test's purpose is to find the different powder load charges that look like they are grouping together on a horizontal plane.

If your groups spread up and down...(vertical)... then adjust the powder charge.

If your groups spread left and right...(horizontal)... then adjust seating depth.

Work on getting the correct powder charge first.... then adjust for seating depth later.

The farther you shoot...the more a vertical spread will show itself.
 
One advantage of the ladder test is that it will limit how much changing a lot of powder can have on your load. If you're smack dab in the middle of a wide "forgiveness window," the tiny variances in lot to lot won't make much difference.

I use ladder tests to compare powders - having a wide window vs. a narrow window is one consideration for me in powder selection.

I think one consideration that makes guys say that it doesn't tell them anything, or that it is repeatable is range. If you're shooting at a range where the difference between a couple tenths of a grain isn't enough spread to make a difference larger than your normal disparity in group size, then it doesn't seem to reveal much. With really high BC bullets, a little change in velocity doesn't mean much vertical drift, so I try to pick my range based on how much accuracy I expect against how much extra drop the slow loads will have.

Being stingey with powder is another way to cripple the test. If you shoot GROUPS of each charge, in the round robin style, such that you can see where the charge is grouping, rather than the individual bullet struck, it tells you more. If you're shooting 300-500yrd ladder tests where a group might be 2-5", it's really hard to tell if single shots of a charge really represent where that charge wants to fly. Say a 58.6grn charged shot would have been the high flyer out if its group of 3-5 shots, then your 60.1grn charge shot would have been the low faller out of a 3-5shot group, they might stack together and make you think you're in the window, when you aren't. I shoot groups, then mark the targets where each group would have centered, then use THOSE marks as my guide posts for picking a charge weight.
 
Ladder test was a train wreck. Shot 11 rounds at 150 yards. Had more horizontal spread than vertical, rounds all over the place. Guess I'll go back to the old way.
 
I don't think the caliber helped you any. Being such a tiny bullet it's just too affected by wind. It would have revealed a lot more if you had done it at a longer range, but maybe that wasn't available.

I have one and it's a favorite rabbit and squirrel gun. I don't like 17s for predators, too many splash wounds. I have shot a few with it though.

Ladder tests are more effective with accurate rifles and bullets with good BCs. I wouldn't abandon it for future use with heavier calibers.

But, in this case, I think you are right. Go the old way.
 
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