Ladder test help

Verminator2 · Post by **Verminator2** » Mon Jul 23, 2007 12:27 pm

I am confused on what might be a node here. The bullet is 39gr. SBK with IMR 4895.Powder charges went from 26-27.6 in .2 gr. increments. Here's the target.

BTW is this called a ladder test?

WrzWaldo · Post by **WrzWaldo** » Mon Jul 23, 2007 1:02 pm

How many yards did you shoot it at?

Yes that sounds/looks like an Audette ladder.

I'd be tempted to play with #8, I would also be tempted to shoot that ladder again. Load 5 of #8 and see how they group.

Verminator2 · Post by **Verminator2** » Mon Jul 23, 2007 1:10 pm

100. I'll load 5 and see how they go. If the wind ever quits blowing

Gmoney · Post by **Gmoney** » Mon Jul 23, 2007 6:41 pm

Aight I'll bite...

Someone quickly explain the "ladder test" for this poor soul...

WrzWaldo · Post by **WrzWaldo** » Mon Jul 23, 2007 7:27 pm

Here's a PDF of the complete procedure.

Creighton Audette's Incremental Load Development Method (or ILDM for short)
essentially is: Choose a bullet, primer, powder and case brand. Once you have
chosen these things, there are two numbers you need to choose to use this method: A
starting load and a load increment. With that chosen, load 20 rounds, start with the
starting load and increase the charge weight stepwise by the increment you chose for
each subsequent round. Load only one round with each charge weight. Then, using
the same aim point, fire all these rounds on one target and interpret the results. Here
are the details.

ILDM starts on page #2.

jo191145 · Post by **jo191145** » Mon Jul 23, 2007 7:40 pm

There is no quick way. Happy reading

Actually quite simple once you understand the basic concept.

Gmoney · Post by **Gmoney** » Tue Jul 24, 2007 5:20 am

Thank you gents...

Verminator2 · Post by **Verminator2** » Tue Jul 24, 2007 9:06 am

THANKS WALDO!!!! Went and shot today with 27.4 of IMR 4895 and a 39 SBK, and here it is! One of my best groups to date w/ the AR. 5 in .671 and 4 in .421.

WrzWaldo · Post by **WrzWaldo** » Tue Jul 24, 2007 9:10 am

If you have room, try tweaking the seating depth. Remember if you push the bullet into the lands you will get a nasty pressure spike.

What kind of prep have you done on your brass? Do you check runout on you brass necks and the bullets on the loaded rounds?

What barrel do you have poked into that AR?

Verminator2 · Post by **Verminator2** » Tue Jul 24, 2007 9:23 am

These have been fired once(now twice) after trimming, chamfering, and flash hole uniforming. The magazine limits my tweaking, but I might try it. How do you check runout?

WrzWaldo · Post by **WrzWaldo** » Tue Jul 24, 2007 9:28 am

I use an RCBS Case Master. But there are other units available as well.

Hawkeye Joe · Post by **Hawkeye Joe** » Tue Jul 24, 2007 1:54 pm

WrzWaldo wrote: But there are other units available as well.

Here is my runout checker. Lucky for me I have all kinds of stuff like this. Being a Machinist and hot-rodder for about 25 years helps in acquiring such tools. My hat's off to all you reloaders who do NOT have this kind of experience.

What I do is spin the case and check for wobble/runout on the bullet. Hope this helps

Jersey Hunter · Post by **Jersey Hunter** » Thu Jul 26, 2007 8:40 am

WrzWaldo wrote:

Here's a PDF of the complete procedure.

ILDM starts on page #2.

WrzWaldo, That url should be a sticky. It would have saved me from shooting a bunch of junk loads when I started. Makes me wonder if I have the best load now.

Thanks,

WrzWaldo · Post by **WrzWaldo** » Thu Jul 26, 2007 8:57 am

I have been playing with Dan Newberrys OCW method. I am having limited success with it.

jo191145 · Post by **jo191145** » Thu Jul 26, 2007 5:51 pm

Wrz Waldo

Just my opinion but Dan Newberrys method is just not greatly suited to a flat shooter like the 204. At 100 yds the jumps between nodes can be less than half an inch per node.
Add to that a 204's average group size of .5 moa and your basically chasing your tail. I quess I should stipulate here and now that I've never tried the OCW method.

I have on occasion converted the single shot Audette ladder into a 100 yd system using seperate aiming points. I use a target with twenty 1/2'' dots on them and fire my sequential loads in order at them. By removing the OCW's 3 shot group from the data I remove a lot of the confusion. Give it a try sometime. See what you think.