Ladder testing.

[bjsiillinois]

Was wondering the consensus on ladder testing. When your working up a new load, what are you concentrating on first, a low SD, ES, small group. Or do look for a low SD, ES, then start playing with seating depth to tighten up the groups.
The reason I ask, and I know it's been asked before, but I have gotten really low SD, ES, before, and had terrible groups. All at a single seating depth. Then I have had some really good groups, but the SD, ES were not that great.
Should I be looking at the SD ES first, getting the lowest I can find, then start seating the bullets to get the best groups, or looking for the lowest SD, ES and groups together as shot from a single seating depth? I usually use the latter to get my best loads, but was just wondering if anyone uses just lowest Standard Deviation, Extreme Spread numbers, then start loading up different seating depths, to get their best loads.

 

[Geronimo Jim]

It all depends on the phase of the moon.

 

[FeMan]

I shoot a velocity ladder to find the charge range that produces the most stable velocity (minimum velocity increases between loads in the series). Then I’ll tune my brake. Third is the seating depth test. Once I’ve got a good load I shoot at distance and get ES and SD. I might play with primers and neck tension if the the ES/SD are high. In the end though, if it has a good waterline at 1k I don’t worry much.

 

[retired]

a ladder test is not about numbers, it is about what is on the target,
that pretty much answers your question.

 

[dsculley]

+1 on what holstil said. I use my chronograph during early load development to watch for excessive MV which means excessive pressure. After that, I depend on my target. If you shoot a ladder at ranges that you will be shooting after load development you will wind up with a load that shoots.

Another consideration, what kind of chronograph do you use? Are you sure the ES/SD are reliable? I don't have a Labradar or Magnetospeed. Optical chronographs are too susceptible to error for me to rely too heavily on them. I will always trust my target over my chronograph.

 

[mikegaiz]

I use a ladder test to find out if the barrel likes the bullet/powder and find the harmonics of the barrel. Of course I could be wrong.

 

[mikecr]

Ladder testing has nothing to do with ES/SD

 

[mram10]

I don’t use chrono at first. I find the nodes and go from there. I only chrono after finding the node with the best vertical. Works for me.

 

[4xforfun]

Somebody needs to define "ladder test". No groups in a ladder test!!! You are shooting a single round of multiple powder amounts at a single target.

Example......one round at 33 grains, one at 33.3, 33.6, 33.9, 34.2, 34.5.....etc.....

 

[3dogs]

Somebody needs to define "ladder test". No groups in a ladder test!!! You are shooting a single round of multiple powder amounts at a single target.

Example......one round at 33 grains, one at 33.3, 33.6, 33.9, 34.2, 34.5.....etc.....

Not always!
Jim

 

[retired]

yes or it is NOT A LADDER.
LADDER as in steps not groups
what ever you are doing if it is not single steps( like a ladder) it is not a ladder.
duh

Not always!
Jim

 

[4xforfun]

Correct Tod. But, we can shoot double, triple, quadruple...... ladders, and extrapolate some ES (I look more at fps per increases), and some group data. But yes, if you want real data, always shoot each ladder as a ladder, not "groups"



Tom

I can't imagin groups would be any good.....to do a proper ladder you need to warm the tube up, start the test, and shoot at a pace that will not add much more heat to the bbl. I take at least 1 min between shots......2 min for a big magnum. if you are testing 10 different charge weights and you shoot 3 ladders...that is AT LEAST 1/2 hr. Since you don't adjust POA for wind, I can't see any chance for good groups ....unless you shoot indoors.

As far as speed...I don't know....If you are checking the speed of the three 33.3 gr charges, but there are twenty other shots between the 1st and last shot, is the data usefull? That I can not answer.

Tod

 

[Bart B.]

What cartridge and at what range are you testing?

Note that a drop difference at 200 yards per 10 fps of velocity change is only a few to several hundredths of an inch. At 600 yards, it's a few to several tenths of an inch.

Can you shoot your stuff good enough to see that?

 

[bjsiillinois]

Thanks for the reply. I use a lab radar, to watch for excessive pressure, and backup velocity numbers from previous outings.
Low ES, SD numbers usually do show nodes, that's backed with good groups, but not always. Mainly wanted to get a consensus on what everybody else was doing. I'm the same as most, I use good groups for a specific powder charge to load around to get a fine tune so to speak. I'll load .1 charges on both sides to get a final charge weight, then maybe play with seating depth if need be,.then shot at range to confirm load. Was just curious, thanks.

 

[bjsiillinois]

6.5x284 out to 1000 yards plus.

 

[4xforfun]

The best results I have ever had is when I would do my ladders a 1000 yards. If there is something happening...it shows up at 1K.

 

[Stan Taylor]

Yes I would agree totally on that if that is the distance you compete you better have a tune at a 1000yds any less your just guessing.

 

[retired]

i do not know how you can justify velocity equals excess pressure.
bbls are different, primers are diff, temp elevation humidity all different than book listed data.

i have several bbl that exceed expectations with NO pressure issues.
while velocity and pressure are related it is tuff to pick a point and say"that is excess velocity" without
a pressure transducer on the chamber.

Thanks for the reply. I use a lab radar, to watch for excessive pressure, and backup velocity numbers from previous outings.
Low ES, SD numbers usually do show nodes, that's backed with good groups, but not always. Mainly wanted to get a consensus on what everybody else was doing. I'm the same as most, I use good groups for a specific powder charge to load around to get a fine tune so to speak. I'll load .1 charges on both sides to get a final charge weight, then maybe play with seating depth if need be,.then shot at range to confirm load. Was just curious, thanks.

 

[Don Fischer]

I've tried ladder testing. I obviously haven't a clue how it really works. I think the days prior to chronographs were much better days. All we had to think about was how small our group's were. Velocity was whatever the manual said it was and we'd not heard of ES or SD. What we worried about in those days was hitting the target we aimed at no matter how far it might be away! Somewhere along the way, handloading became rocket science!

 

[retired]

not all of us.
and yes, i call this level "ammo crafting", not reloading.

I've tried ladder testing. I obviously haven't a clue how it really works. I think the days prior to chronographs were much better days. All we had to think about was how small our group's were. Velocity was whatever the manual said it was and we'd not heard of ES or SD. What we worried about in those days was hitting the target we aimed at no matter how far it might be away! Somewhere along the way, handloading became rocket science!