**“Audette ‘Ladder Load’
vs. Newberry ‘OCW’ Test Methods…”**

This Week’s Tips or
Tricks…

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*Note: all below CBTO measurements noted were
taken using a Hornady Bullet Comparator attached to a
Hornady Dial Caliper as shown below. Please also note that for all CBTO values
documented below, I would also need to subtract 1.0035” from every CBTO
measurement to get the corrected CBTO length.*

*Example: I measured CBTO with the Hornady Bullet Comparator attached to the Hornady Dial Caliper and noted the value as 2.8200”. To find the length that you will need to
subtract for your particular tool to get corrected CBTO, close the Dial Caliper
jaws all the way down with the Bullet Comparator Tool and the correct size
comparator inserted and document the value of the Dial Caliper when fully
closed, in the case of my particular tool this value was 1.0035” when fully
closed. So to find corrected CBTO I
would then calculate 2.8200” – 1.0035” = 1.8165” CBTO. If you are using a digital caliper, simply
close the jaws and press the ‘Zero’ button on your calipers to achieve your
corrected CBTO.*

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**TIP:** In one of my previous articles I introduced
you to the exploration of a test called the Audette
“Ladder Load” whereby we use a SWAG to give us a good Optimal Charge Weight
starting point for our reloads and we will see how well those Ladder Load test
results worked out. This week I want to
introduce you to another method of finding the Optimal Charge Weight called the
“OCW” test created and developed by Dan Newberry to be the “better mouse trap” for some…because a “Ladder
Load” doesn’t always work and I am going to show you how and why they may or
may not always work and also how an OCW test can complement or help to solidify
your results…or as Mr. Newberry would argue, the “OCW” would be the better choice!

I am not going spend a great deal of
time nor go very deep into the “OCW” test method as you can get a very in-depth
understanding and explanation of the test by clicking on any of the blue links
noted in the sentence above or hereafter which will take you directly to Dan
Newberry’s www.ocwreloading.com website.

If you are completely new to the
“Ladder Load” testing method concepts and/or the aspects of how to identify
signs of pressure and dangerous characteristics when reloading, please refer to
and read my prelude to this article by clicking on the following link where we
go much deeper into the aspects of the “Ladder Load” and identifying unsafe and
dangerous characteristics of your reloading practices:

**Ladder Load - Finding Optimal Charge Weights**

*Note: All of the referenced values, data, and/or
observations noted above and hereafter are strictly dependent to the rifle,
bullet, powder, primer, brass, and conditions in which this test was
conducted. These results are all to be
used as informational only purposes for you to see how the before and hereafter
mentioned reloading methods can be applied to your particular reloading methods
and practices and none of the following data should ever be used without proper
understanding of metallic cartridge reloading and the exercise of safe and
SAAMI compliant reloading practices and procedures. *

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First, let’s recap what the goals
are and the types of data we are primarily targeting for by conducting an
Optimal Charge Weight test or a “Ladder Load” or “OCW” test:

·
Identifying where our optimal charge
weight(s) starting point(s) may be…

·
Identifying where our * MAXIMUM*
safe charge weights may end…

·
Identifying where charge weights may
begin to produce __HIGH PRESSURES…__

·
Identifying where charge weights may
begin to produce * EXTREMELY DANGEROUS PRESSURES*…

·
Identifying whether or not our
firearm/brass/bullet/powder/primer combination was a good choice or if you may
be “off in the weeds” with your components selections…

·
Finding our best performing handloads in the shortest amount of rounds...

·
Finding our best performing handloads with the least wasted development costs…

·
We must ensure accurate and
consistent results in order to avoid any “false positives”, so you should
conduct this test with your firearm secured firmly into/onto a sled, tripod, or
with a bipod/monopod

·
For the best results when conducting
a “Ladder Load’ test, you should conduct it at 300 yards if possible…

·
For an “OCW” test, you can conduct it at 100 yards…

Next, let’s take a look at the (2)
potential Optimal Charge Weights we identified in another “Ladder Load” test
done with AR-Comp (target analysis shown below for reference)…

·
Node #1 - ~21.7 gr. grouped around
+/-1.00” vertical spread at 300 yds…

o
This group had a good SD of just
10.3 fps and would allow us the tolerance of +/-0.3 grains charge weight
variance and still hold our group size.

·
Node #2 - ~22.4 gr. grouped around
+/-0.50” vertical spread at 300 yds...

o
This group has an even better SD of
just 9.5 fps and would allow us the tolerance of +/-0.2 grains charge weight variance
and still hold our group size.

o
While this group has a smaller node
for “error” with +/-0.1 grains less charge weight variance, this node does
however provide ~90+ fps more muzzle velocity than Node #1 which is critical to
help buck the wind in those longer range shots!

After we clearly outlined and
analyzed **ALL** the data we had from that test we seen our final
results were…

·
* MAXIMUM*
safe charge weight…22.9 gr…

·
* HIGH PRESSURES* began to exhibit…22.7 gr…

·
Node #2 at ~22.4 gr. grouped well at
+/-0.50” vertical spread at 300 yds and additionally
the powder charge did NOT exceed our * MAXIMUM* safe charge weight determined to be at
22.9 gr…therefore…

·
**OPTIMAL CHARGE WEIGHT...**was determined to be ~22.4 gr which was under our * MAXIMUM*
safe charge weight and incidentally also provided the least vertical spread of
0.50” during the 300 yd “Ladder Load” test.

·
Note: previously in the other
article we said a Ladder Load * should*
demonstrate an incremental POI on the target such as climbing a ladder because
we are increasing our powder charges incrementally thus increasing both the
pressures and therefore muzzle velocities of each incremental charge weight
tested also.

o
**PRO TIP #1:** *If you do NOT see any sort of noticeable
vertical ladder rung stepping on your target, you may want to ensure your scale
is properly calibrated and/or further examine all aspects of your reloading
process to see where variations in your process may have been induced and
therefore leading to the inconsistent and potentially erratic characteristics
of the test results. However, note that
if your meticulous inspection conclusion finds that no particular aspect was at
fault, re-run the same Ladder Load test to see if results are consistent. If the results are consistently erratic, you
have a rather definite conclusion that this particular “marriage” of components
is NOT optimal and you should re-evaluate your choice(s) of components. *

Once we had our Optimal Charge
Weight of 22.4 grains of AR-Comp selected from the Ladder, we then proceeded to
check our zero and group at 100 yards with (15) shots! As you can see from the bottom row of
pictures in the above cluster, we ran (15) shots into a group at 100 yards and
got a 1.179” Extreme Spread (ES) taking into account (3) pulled shots due to
shooter error and a group size of just 0.770” Extreme Spread (ES) over the (12)
Shots which excluded the (3) pulled shots.
Now, when we identified the initial 22.4 grain charge weight from the
“Ladder Load” test above, you can see above that the +/-0.2 grain variance gave
us just 9.5 fps SD (see chart in top row, middle). So, after we had normalized all of our charge
weights at the stable and consistent 22.4 grains charge weight…the SD came down
even further to just 8.9 fps over the last (14) shots…the cold bore Shot #1 was
a bit faster than all the follow-up testing shots….*<--VERY IMPORTANT OBSERVATION TO DOCUMENT
AND PAY ATTENTION TO HERE IF WE ARE ROUTINELY NEEDING TO BE VERY ACCURATE ON
COLD BORE SHOTS SUCH AS AT A RIFLE MATCH WITH A COLD BORE BULLSEYE STAGE!!!*

So that is all fine and dandy, not
that impressive for a group size at 100 yards at just 0.770” ES with (12) shots
and 1.179” ES with (15) shots. But let’s
see what the results were when we stretched it out to 3x the distance at 300
yards!

On the second day we returned to the
range but this time at the 300 yard line, we got the trigger man under control
on the bang switch and I was able to shoot a (10) shot string at 3.041” ES…so
just a pinch over 1 MOA at 300 yards…not bad, but still not good either because
look at the huge shot disbursement for this group…sort of looks like two
opposing armies preparing for flanking maneuvers with those two separations in
the group.

Next, it was time for some magic! Watch what happened when we take a ‘mediocre’
group with a set charge weight and start optimizing it by tuning seating
depth! In the target below, you will now
see that by simply changing ONLY the bullet seating depth by -0.005” from the
above target group seating depth…we reduced our group size to just 1.707” ES over
an (8) shot string excluding (2) fliers…and a (10) shot group at 3.505” at 300
yards. Now, why the flyers? Yes it was me again, but this time low light
right before dark pushed me to get this string off before we ran out of light
and the range closed down for the day…damn short winter days!

I see one question already brewing
in your mind…”why did you choose to back off in seating depth and seat farther
away from the lands instead of closer to the lands?” The reason is because I know how this rifle reacts
to other loads and it typically likes them backed off of the lands just a tiny
bit farther. In this case I used my
“Reloading DOPE” if you will to predict the most accurate direction of seating
depth tuning to produce a better group for this particular load development
combination. In fact, I may even see a
bit tighter group size if I backed off just a tiny bit more yet. However, when you run this test, you may not
know your rifle as well initially, so I would recommend loading one test group
string at +0.005” and another at -0.005” from your initial seating depth and
whichever way gets tighter…continue in that direction!

Ok, so the “Ladder Load” test worked
pretty well…wouldn’t you say? Not bad
for having a sub-MOA group within just a measly (24) round “Ladder Load” test
string, (10) round 100 yard group string, and another 2-(10) round group
strings at 300 yards to test seating depth totaling just a mere (54) TOTAL
shots to achieve a sub-MOA group at 300 yards with a brand new load for an
AR-15 rifle of all things (shown below for reference)!!!

Alright…now onto the “better mouse
trap” as some may argue it! Many
reloaders both new and old may already be working your load development scheme
more like a modified version of the “OCW” test created and developed by Dan Newberry but you are inaccurately referring to it as doing a ‘Ladder
Load’ test instead, shame on you…how dare you [LOL]! So, let’s identify the difference and see how
a true “OCW” test is really conducted per its creator and how
dramatically it differs in execution compared to a “Ladder Load” test.

Using our Broken Box R LLC “Charge /
Seating / Tension Tuning Test Target” and data tracking sheet, we will layout
our load development test charge weights in ~+2%invervals from the Minimum
Suggested Charge Weight for this load (in this case we will just move up by +0.3
grains incremental charges (i.e. 20.5, 20.8, 21.1…) for the simplicity of
illustration within this article. Now,
you will load (3) rounds at each of the designated charge weights and clearly
mark and place them into your reloading box…** NOTE: it
is very important that you keep EVERYTHING the exact same from (3) round test
string to (3) round test string accept the incremental jump in the powder
charges to be tested!**
Once you have (3) rounds for each of the test strings, in the case of
this “OCW” test we have (9) strings, you are then ready to hit the
range (see below data tracking sheet for illustration on each of the (9)
strings to be tested). Note: you will
also want to load up an extra 1-2 rounds at each of the designated charge
weight intervals in case you have any fliers and need to re-shoot one of them
in order to achieve a (3) shot group…

After you make it to the range, you
are going to set up your target and start shooting your “OCW” test in the following manner in round-robin tiers as
illustrated below. You will start with the
Tier #1 String and move through all (9) test charge weights, then start over
back at the beginning of the Tier #2 String and continue so on and so forth
until you have shot at least (3) good rounds for each of the (9) tested charge
weights as we had in the case of this test.
Ensure you allow your barrel to cool in between each of the fired shots
and strings.

After completing this entire “OCW” test process above of tiered round-robin style shooting at
all the designated charge weights…per Dan Newberry’s method, you will then triangulate
each of the group’s centroids and find (3) adjacent groups that have the most
similar Point of Impact (POI) in relation to the bullseye of the target using
said centroids. So what does this look
like and mean?

Throughout charge weights 20.5,
20.8, 21.1, 21.4 and 21.7 grains the centroid POI continued to oscillate about
the center axis of the bullseye as seen below.
Once the charge weight reached 22.2, 22.4, and 22.6 grains, the centroid
POI became relative to the same spot in relation to the bullseye. Then at 22.9 grains the POI began to
oscillate again also shown below.

Now that we have found (3) adjacent
POI centroids in the same relative position to the bullseye, we would then
determine the median point of those particular charge weights tested…which in
this case would be 22.4 grains…and now you have just determined your Optimal
Charge Weight per the Dan Newberry “OCW” test method for this particular load development test. *Note: obviously the below illustration is a ‘simulated’
course of fire only as I was unable to conduct a live course of fire using this
method prior to writing this article; however, I do plan to visit the range
within the near future with this very same load development combination as ran
above using the “Ladder Load” test and compare the actual live fire results to
that of the “**OCW**”
test method for determined Optimal Charge Weight and see how they both
agree/disagree!*

What do we do now that we have
established our initial Optimal Charge Weight from our “Ladder Load” or “OCW” test??? Now you likely
have a bit more load development ahead of you to begin optimizing seating
depths, tweaking your case prep practices to reduce runout, crimp, neck
tension, shoulder bump, and so on and so forth in order to find that very best
3/5/10 shot grouping that this particular load and firearm is capable of
producing at a given distance.

Alright, now that you know what the
procedural differences for each of these two methods are…let’s take a closer
look at where each testing method may be better suited or less adequate. First, before anybody decides to just hop up
on their broom stick and fly off the handle about the way I may have classified
any of these factors per the designated test method(s)…understand, this is my
professional and analytical opinion in regards to these classifications. I have attempted to remove any favoritism or
bias from this breakdown and favored neither in their aspects of my
opinions…because the fact of the matter is that I use both of these methods
routinely, but tend to lean more heavily toward using the “Ladder Load” method
primarily because it is a quicker and easier setup process for me and I am very
meticulous in the detailing of my reloading data capturing and analysis aspects
anyways. If you are a data junky like
myself and the analysis part of taking the “Ladder Load” to the “nth” level
like I do above doesn’t bother you, then give the “Ladder Load” method a
shot! If you have no desire nor patience
to “nth” it…you will want to take the “OCW” test method route!
If you have any further questions or comments regarding this article or
its contents, please feel free to email us at sales@brokenboxr.com.

So what is the moral of this story
folks...there * IS* indeed more
than one way to skin this cat and you should ALWAYS access

For any additional questions
regarding information or to purchase your Kestrel 5700 Series Weather Meter,
MagnetoSpeed Chronograph, or a Bullseye Camera Systems please click on the
following link for Broken Box R LLC’s website as we are an Authorized Dealer
for both the Kestrel and MagnetoSpeed product lines or give us a call at
888-869-3150 Ext. 1 today!

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Do
you have a Tip or Trick regarding reloading that you would like to see
posted? Please send us your Tip(s) or
Trick(s) and we will see about getting them posted!

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* *

*Written By: Kyle R.
CEO of Broken Box R LLC*

* *

*Copyright © 2017 Broken Box R LLC – All Rights Reserved*

*This article was first published on February 17 ^{th},
2017.*