Ladder test question

T

turtlehead

New member
I plan on loading a ladder test for a bolt action 223. Each powder load will increase in .10 increments.

Will shooting this test at 100 yards even give me any useful information?

I ask because my spotting scope is garbage at 200 yards (furthest I can shoot locally).
 
A true ladder test needs to be shot at 300 yards or further.

Don't waste your time and powder trying to go in .1gr increments. Bare minimum do .2gr increments. I generally do mine in .3gr increments and it gives me the data I need.


Sent from my iPhone using Tapatalk
 
The farther the distance the better it is for a ladder test. If all you have is 200 yds it is better than 100. But as stated it would be better at 300.

Since your scope is a limiting factor in this game you can do a somewhat modified test. For example load 5 rds at 21.0 grains than load 5 rds at 21.4, than 5 rds at 21.8, and so forth until you get near max load. I like 5 shot groups regardless of caliber and this will show you a grouping that your rifle likes best at 100 yds.

Once you have the smallest group use that load for your rifle. But if your scope is that bad you may not know if it is the scope or the rifle that causes the bad shot groups.

Good shooting.
 
I have a nice 4-16 scope. It's my Harbor Freight spotting scope that's no good. I need to know where each shot hits and that spotting scope is really iffy at 200 yards. At 100 yards the rifle scope is fine.
 
I asked Bart Bobbitt if one powder charge can be more accurate than another.
That was because if I work up firing 5 shot groups, see what I think is a sweet spot, come back the next day and it not repeatable.

He says if I fire enough shots in each group I will get repeatable results, that is all powder charges shoot the same.
 
Has anyone ever tried to set up streaming video from a tablet or phone to another device, so a device up at the target can show pictures at the bench?
 
"I plan on loading a ladder test for a bolt action 223. Each powder load will increase in .10 increments."

first off, I don't do "ladders". I do incremental load adjustments. Just my opinion but if you're talking about increments of .1 grain changes, you're wasting time, powder, and barrel life.
 
I'm not understanding why your spotting scope is an issue. However you end up doing your test, won't you retrieve the targets and then measure the groups regardless of what you see through the spotting scope as you're shooting them?
 
Because each successive shot has an increased increment of powder. You need to mark down where each one hits. And then you look for groupings within ranges of charges to find your sweet spot. At least that's what I've read.

But I won't be doing that particular test now. I'll just load 5 at 26.0, 5 at 26.3, 5 at 26.6 and so on and shoot for groups.
 
Huh. Maybe I don't know the best way to do it, but I've never done, and I don't know anyone who's ever done, what you're proposing.

Most everyone I know just does it as you say in the second part - shoot a group with one charge, another group with another charge, etc., then select the load with the best performance and sight the rifle in with that. I prefer to set up multiple targets, fire one shot with charge 1 at the first target, then one shot with charge 2 at the second, etc. and continue in sequence until I have the same number of shots on each target. That way I can eliminate, or at least reduce, any effect of factors such as the barrel heating, my own fatigue, etc.

And then I evaluate the performance by calculating CEP rather than measuring group size, but that's a whole 'nother discussion.
 
Read Newberry's OCW system at the link Qrz provided. It works better at shorter ranges than the traditional Audette ladder does (though even better at 300), because it averages 3 shots per charge weight. It is fired as a round robin to even out the effects of barrel temperature, changing conditions during the shooting, etc. Even so, I evaluate them with a running average of three charge weights, as part of the idea is to find a load that works well over a span of charge weights so you don't require excessive precision in charging cases. The running average gives you the net effect of 9 shots instead of just 3, so its statistical certainty is better.

Download the free version of On Target and use it with photos or scans of your targets. The locations of the centers of the groups is what you are after, and this tool helps with finding them accurately.

For those not following or wanting to know how an Audette ladder works, here's an old thread in which I helped someone evaluate a 300 yard ladder starting at post #13. He eventually got under 1/3 moa this way. So it works, but the evaluation just isn't always trivial.

For the running average evaluation of an OCW round robin fired at 100 yards, the image below shows the results of one I did for a board member here. The purple diamonds are the 3-shot centers from the round robin targets, while the yellow circles are the running average of three targets, and you can see it is easier to tell from those what the charge range is over which point of impact stops changing much. That's the sweet spot load.

POND1b_zps80cfc921.gif
 
Well, I'm brand new to reloading and this will be the first test of my work. Just hoping to learn something the first time out.

What does CEP stand for?
 
I'll spend some time with Newberry's article as well. Thanks, Unclenick - I learn something every time I read one of your posts.

CEP = circular error probable, which is the way the military evaluates the precision of ordnance from small arms to ballistic missiles. There's a good discussion of it on Wikipedia. The advantages of using it instead of group size are primarily that it uses all the data from the test rather than just the two points furthest apart, and it's independent of the number of shots in the group, though obviously more shots will provide a better estimate of CEP. I practice, I just calculate average deviation (average distance of each shot from the group center) which is easier and correlated at about .9 with CEP - close enough for me.
 
A ladder test doesn't tell you much about anything except where one load hits the target in comparison with another. Tells you nothing about the accuracy of any load out of your rifle.
Wikipedia is not a reliable source of information about anything. Anybody with internet access can post anything they want there.
 
You must log in or register to reply here.
Back
Top