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OCW/Ladder Testing - Practical Results

TrapperT

Sergeant
Full Member
Minuteman
Jun 10, 2005
128
1
Temperance, MI
I thought it might be beneficial to relay my experience with the OCW and ladder methods for developing loads in a variety of rifles at different distances.

I have reloaded for a number cartridges including .338LM, .30-06, .308, .223 (AR platform), .243, 7/300WSM. I have used both a modified OCW and ladder test to develop loads at distances from 100 yards to 1000yards. I have shot all of these cartridges to 1000 yards and have taken my .338 to one mile.

My main load development method has been a modified OCW. I determine an approximate max load and then depending on the cartridge capacity, I'll determine what increments I want to work in (i.e. .2, .3 or .5 grain). I'll then load three charges at each increment until I reach my pre-determined max load. I'll shoot these in the traditional round-robin manner and then pick the best "group". This is where I deviate from the OCW as described by Dan Newberry. I feel that my loading method is precise enough that my powder charge will not deviate enough to cause issues (so I am not finding a “middle node” between two charges). Once I find a load, I may also play with seating depth using the same procedure. I have done most of my OCW development at 100 yards.

So how does this work at distance? Well, I developed a load for my .338LM doing this and have shot sub .5 MOA out to 1000 yards numerous times. As a matter of fact, my son shot a 5 shot group at 1000 yards that measured 2 5/8". Yes, I have a picture and I measured it and all 5 rounds were shot in a row. I have done similar things with my .243 Win (Yes, these are both custom guns).

Here is my OCW for 300SMK and my .338 (it's pretty easy to pick which load I chose)

66eq2g.jpg



When I started F-Class, I decided to develop my load using the method (with some modifications) which Jason Baney describes over at 6mmBR (http://www.6mmbr.com/laddertest.html). Since I would be shooting at 1000yards with this gun (almost exclusively), I thought it would be best to develop a load at the distance I would be shooting. This method yielded vertical spreads as little as .75”. I then did seating depth testing at 300 yards using the round-robin method to hone in on a final load. The load I have chosen has done extremely well for F-Class.

Here is a ladder test at 1000 yards

ixxp8l.jpg


So, what is my point in posting this? Based on my experience, both methods do a great job of developing loads. I am also fairly confident that load development at 100 yards with long bullets, does indeed produce acceptable results at distance. Likewise, ladder testing at distance has produced loads which are very competitive for F-Class (specifically the open class in my case).

So which method is my favorite? Well, that depends. For F-Class I would use ladder testing as I am trying to minimize vertical and this method does a very good job of identifying that load. If all I have available is a 100 yard range, I’ll utilize the OCW and wouldn’t have reservations using it for mid-range F-Class (BTW – I have done this using my .243). Again, the beginners my find this useful, whereas the established shooters probably have a preferred method which may be one of the two I described or something totally different. YMMV.

BTW - These loads work in my rifle and my rifle only. They may not work well in yours.

Tony
 
Re: OCW/Ladder Testing - Practical Results

Dan and I discussed this, among other things, in length Saturday over lunch.....OCW vs. Ladder.

The main purpose of OCW is to find a load with enough inherant tolerance to override many of the commonly feared variables found in the system. His curiosity for this was the fact that FGMM ammo works well in so many different rifles.

OCW is a quantification of the function of the physics of barrel harmonics; and is best suited to what he calls "practical riflery", which has nothing at all to do with benchrest, or f class, or any other disipline that revolves around literal group size. When Dan says "find THE load", he means the load you can count on to hit things and kill things, at any given time, under any given conditions.

Anyone can work up a half minute load, on any given day, by whatever method, in July....but will it still shoot half minute, and to the exact point of aim in the middle of February? Will it shoot that same way with another brand of brass, or lot # of powder....or God forbid another rifle?

As a disciple of the OCW principles, my load may only ever produce 3/4 minute groups....but it will do it consistantly across a vast array of variables, and time. Most of the time though, accuracy is much better than that.

And for what it's worth, plain old factory rifles with plain old factory barrels can be made to shoot FAR better than commonly accepted simply by working up an OCW load in adherance to OCW principles.

Ladder can, and will eventually, mislead you, IF the goal is what we seek in OCW. He can explain it far better than I can, probably because OCW does all that I need, and I don't care about ladder enough to argue anything.

Most of the "problem" is that OCW has been twisted into something that it's not, and that comes from people simply not understanding what it is, or what it's for.......
 
Re: OCW/Ladder Testing - Practical Results

Thank you both for your insights!
I am a novice reloader, and have been trying to research both techniques for load development. I was definitely excited in reducing the amount of loads made to find a good powder charge, which both techniques seem to do to a point. The range I belong to only has a 300yd max range, which limits my testing. It seems most that believe in the ladder test recommend taking it further than 300yds, which just isn't an option for me. I had planned on trying the OCW testing just due to the fact that I am limited on range. This modified version may also be another option to try.
I am wondering though, anybody that feels a ladder test can give good reliable information at 300yds, please give me your input.
 
Re: OCW/Ladder Testing - Practical Results

Question for Trapper T:

Why do you have multiples of the same powder weight on a ladder test? I usually test at 600 in .1 increments and I usually get 3 to five weights that group within an inch or two vertically of one another. It would seem like shooting more than one weight of powder on a ladder test is a waste.

Also, I really haven't embraced OCW yet. For long range I think ladder is the way to go. OCW just seems like warmed over shooting groups at different weights.

As far as Dan Newberry's comments that ladder testing can often give erroneous results because of hold errors really shows he doesn't understand ladder testing at all. If the shot is called good on any test...that's as good as it can get. If it's a bad call, you make a note of it and if it is within a load range that matters you may want to redo the test.

And the theory of harmonics of the shock wave is just that...a theory. It's plausible, but so are a lot of things that are not true.

Thanks for the thread. It's interesting. Thanks for sharing with the rest of us grunts.
 
Re: OCW/Ladder Testing - Practical Results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: himaster</div><div class="ubbcode-body">Question for tripwire:

</div></div>

You're asking the wrong person dude, I don't fool with ladder testing.......your attention to detail is quite telling.
 
Re: OCW/Ladder Testing - Practical Results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tripwire</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: himaster</div><div class="ubbcode-body">Question for tripwire:

</div></div>

You're asking the wrong person dude, I don't fool with ladder testing.......your attention to detail is quite telling. </div></div>

My bad, it was a question for TrapperT...the OP. Got my posts confused. I only pay attention when it matters and if I screw up on this forum...who cares?

So I'm editing my other post to read "question for Trapper T" instead of "question for tripwire."
 
Re: OCW/Ladder Testing - Practical Results

"And the theory of harmonics of the shock wave is just that...a theory. <span style="text-decoration: underline">It's plausible</span>, but so are a lot of things that are not true."

Ain't that the truth!
 
Re: OCW/Ladder Testing - Practical Results

Himaster:

The reason I use multiple shots during ladder testing is because I feel that one shot does not fully "describe" that node. For example if I had taken one shot each with the charges shown on my ladder test, one could draw the conclusion that the 64.3 load was within the "preferred load window", but it really isn't. When it comes to vertical dispersion, one shot cannot adequatley describe the group characteristics for that particualr load. In terms of statistics, that one shot could be an outlier and without additional data points, you'll never be able to determine that.

Hopefully this clears up why I do multiple shots with a given charge.

Tony
 
Re: OCW/Ladder Testing - Practical Results

Ladder testing with single rounmds seems best used to quickly eliminate charge ranges that DON'T shoot well rather than supposing to indentify what does. The "best" charge (and OAL) is rarely - if ever - a particular point, +/- nothing, so IF we use small increments it's pretty easy to see the effect of a group tightening and then opening.

Once I find the charge (or OAL) node range that suggests it's a winner THEN I retest with 3 or 5 round groups to confirm it's good or not so good. Saves both time and money to do it that way.
 
Re: OCW/Ladder Testing - Practical Results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fuzzball</div><div class="ubbcode-body">Ladder testing with single rounmds seems best used to quickly eliminate charge ranges that DON'T shoot well rather than supposing to indentify what does. The "best" charge (and OAL) is rarely - if ever - a particular point, +/- nothing, so IF we use small increments it's pretty easy to see the effect of a group tightening and then opening.

Once I find the charge (or OAL) node range that suggests it's a winner THEN I retest with 3 or 5 round groups to confirm it's good or not so good. Saves both time and money to do it that way. </div></div>

+1 for fuzzball

If I get four tight shots with one in that range that is an outlier, I might test that whole range with 5 to 10 shot groups. Actually...in reality, it's never happened.
 
Re: OCW/Ladder Testing - Practical Results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cstmwrks</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kombayotch</div><div class="ubbcode-body">Chris Long's Shock Wave Theory explains the physics behind why OCW works, if you enjoy understanding something in depth:
http://www.the-long-family.com/OBT_paper.htm
</div></div>

Interesting read. If I'm not mistaken and the shock wave theory is correct than the tons of money spent on fluted heavy barrels has been a waste, at lease if it was done under the guise of getting a more accurate barrel.

</div></div>

I've never hear claims of it giving you a more accurate barrel. It's primarily done for weight reduction and heat dissipation...
 
Re: OCW/Ladder Testing - Practical Results

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TrapperT</div><div class="ubbcode-body">Himaster:

The reason I use multiple shots during ladder testing is because I feel that one shot does not fully "describe" that node. For example if I had taken one shot each with the charges shown on my ladder test, one could draw the conclusion that the 64.3 load was within the "preferred load window", but it really isn't. When it comes to vertical dispersion, one shot cannot adequatley describe the group characteristics for that particualr load. In terms of statistics, that one shot could be an outlier and without additional data points, you'll never be able to determine that.

Hopefully this clears up why I do multiple shots with a given charge.

Tony </div></div>

And thus why some of us prefer OCW......