Help with ladder test

S

sblanch

Private
Minuteman
Oct 28, 2009
96
0
43
Iowa
#1
I'm trying to develop my first load and decided to use Audette's ladder test. The problem is that the last 11 of 20 rounds went into one ragged 1" hole.

What, if anything can I deduce from this?

Here's the details:

Savage model 10 chambered in .308
26" 1 in 10 factory barrel

Remington brass, FL sized, .002" shoulder setback, trimmed to 2.005"

9 1/2 primers

41.7-45.5 grns varget in .2 grn increments

168 grn SMK seated .002" off the lands

2.821" overall length

Distance of 100 yds

I guess my biggest question is where to go next?

Thanks
 
#2
Re: Help with ladder test

Yup, looks good, looks like it's not going to be picky, pick one and go....
smile.gif


Might have to move target a bit further out to get a better idea of how they do.

Topstrap
 
#5
Re: Help with ladder test

Right in the middle of the 11 one hole rounds is the charge you want. Makes the
load very forgiving. Wish all guns shot like that. Move out to 200 or 300 to test in
the future with it.
 
#6
Re: Help with ladder test

Don't get me wrong. I was thrilled to shoot that group, and I'm amazed at the difference handloads made. Those were the second twenty reloads I've ever shot. Before that I was shooting what resembled a tight shotgun pattern with factory hunting ammo.

I was just hoping to get more information from the test to nail down a good load for my rifle.
 
#8
Re: Help with ladder test

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wards75</div><div class="ubbcode-body">I thought the ladder test was supposed to be done at longer distances...or maybe i didnt read it correctly, havn't tried it out yet, but, sounds like it works.
See if this helps....

Ward


http://www.6mmbr.com/laddertest.html </div></div>

I used that very article to get going. I did overlook the distances referenced, so I'll move out to at least 200 next time.

BTW, I did color my bullets with a few colors of dry erase markers and was suprised how well it worked.
 
#9
Re: Help with ladder test

Ward75 great article you posted (http://www.6mmbr.com/laddertest.html)
I spent 22 years as a Combat SAR in the Navy and "distance shooter" we used nothing but .308 match grade ammo, same for the MK 23 SOCOM I used to carry. I'm a .30-06 shooter and prefer nothing else. Don't get me wrong, hey I loved the .308!Especially in my M-14 DMR. Now I'm making rounds for a Winchester Pre 64 Model 70 .30-06. Blonged to my Father retired Special forces Green Beret "Project Delta" 6 tours and 23 years. Sorry I have braggin rights on the mean ol'Bastard, God rest his soul. The rifle is accurate as hell but I just gotta be anal and go one step further. Also have an 1903A3 on the way that I'll be workin on soon. I'll be lookin forward to tryin this method out. I'll let you know how it goes. It sounds pretty solid to me.
Thanks again and be safe to all,
Larry
 
#10
Re: Help with ladder test

Another variation on this test: if you are planning on using the load at longer distances, then you DEFINITELY want to use a chronograph for this test. Record the MV of each shot. When you find different charge weights producing a cluster of MV close to each other, then pick the load that produces the middle velocity and go from there.
 
#11
Re: Help with ladder test

Today I used the info from my first test to narrow down my options. It went pretty well but I did end up with a question or two.

This is what I did:

Using the original ladder test results I threw out the first eight shots that were strung out, leaving the eleven charges that formed the tight group.
I then broke that group into five incremental charges and loaded five of each charge weight starting at 43.8 and ending at 45.5
After that I fired five groups of five at 200 yards. This was the result with each charge.

1. 43.8 grns-2.35" group
2. 44.2 grns-2.74" group
3. 44.6 grns-1.13" group
4. 45.0 grns-2.10" group (1 flier the other 4 at .97)
5. 45.5 grns-3.82" group

All the groups were pretty evenly spread except as noted in #4

I plan on repeating the test to be thorough and if the results are similar, narrow it further by loading five each of 44.5 grns, 44.7 grns, 44.9 grns and 45.1 grns.

Now the qustions:

Does my method/plan seem reliable?

Should I mess with changing my jump to the lands?

Is the sudden change in grouping between loads 2&3 and 4&5 common when changing charge weight by .4 or .5 grns?

What would be next on your list of things to tweak, if anything?

Thanks for the help.

BTW I don't have a chronograph. Is it a worthwhile investment?
 
#13
Re: Help with ladder test

5x5Guy,

You're doing fine so far. You're making mistakes but at least you're learning from them. The Jason Baney article is great. I've been using the ladder for a number of years now and his method refines it to the Nth degree.

Powder charge 1st, seating depth second, primers and/or neck tension 3rd/4th.

A ladder is not fool proof. Their are inconsistencies and difficulties with using it such as shooter ability, weather conditions, etc but it can certainly narrow down the field of possibly component combinations.

If you have the distance I think you should push it out to 300 or even 400-500. It can tell you more. But only if you are confident of your shooting ability, the weather is good and wind consistent.

To answer your questions.

1. You've deviated a bit from norm. A case size of a 308 should have a max of 1% or 4.5 gr between charges. Other wise you have a chance of skipping past good load. At least in your second test you're getting it down to .4 gr. I'd even to to .2 or .3 for refining load development.

2. Don't even touch the seating depth until you finalize the powder charge.

3. Nodes will show them selves and it seems you've come upon a node. Work within that node to refine your load.

Where a chrono will help, especially for long range stuff, is refining your testing so you can get your Extreme Spread (ES) and Standard Deviation (SD) down. It's not too hard to find accurate loads at shorter distances where their ES/SD are not good. It's "WAY out there" distances you'll need small ES/SD's. If not you'll get shots hit high and low from your aim point. Jason Baney's 1000 yd ladder shows that. Now that you've taken the ladder this far, reread his article. I'll bet some things in it will be much more clear. You might even have an ephipany or two.

Keep us up to date on your progress.

Oh, and I'm currently running my own ladders in my new Surgeon 6.5x47 Lapua. Shot 10 ladders yesterday. Normally only shoot 1-2 but weather was perfect all day long and I just couldn't stop myself
cool.gif


Alan
 
#14
Re: Help with ladder test

Your load sits between the 44.5 and 45.0. I would load 44.7 and go out and shoot
3 or four 5 round groups. One question, did you call the flier at 45.0? I mean did
you know you pulled the shot or was it a surprise when you looked in the spotter?
 
#16
Re: Help with ladder test

Thanks to all who responded. The knowledge that people share on this site is the best I've found on the web and is very appreciateed.

I did re-read the article and picked up on a few things I missed. I think info from several articles I read on the subject got muddled into one as the referenced one is way more in depth than some others I remember.


GSSP mentioned confidence in shooting ability. I suprised myself with my first sub-MOA groups on my last trip out and am eager to shoot longer distances. I'm sure my inexperience will show itself more and more as I go farther out. Not knowing if a big group is a bad load or poor shooting makes for some tough going but I'm having a good time and a few buddies are showing some interest in shooting long distance. A day out shooting with the guys. You cant beat that.

bigwheeler asked if I knew I pulled the bad shot in group 4. I cant say for sure but I do remember thinking it felt "off" as I fired it.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DaveV</div><div class="ubbcode-body">Seems to make the case for OCW
wink.gif
</div></div>

I have no idea what this means.

Thanks again
 
#19
Re: Help with ladder test

Life got a lot simplier and better results when I found the OCW method, see link above first.

A friend of mine shoot this test for his AI 155L Varget http://practicalrifler.6.forumer.com/viewtopic.php?t=862 it was his first try at this method and shot the test at 300 yds by mistake, but he is a fair shot. He now shoots the test at 100 before moving to 300.
 
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