OCW vs Ladder vs Chronograph

[Adam in WI]

Folks, I understand this has most likely been discussed ad nauseam; but I wanted to see what the current favorite method of load development is for non-BR applications. Specifically; what's your preferred method for finding a good load in sporter weight barrels? I read the most recent thread on a ladder test in a sporter 270 where some suggest that reading such a test on a light barrel is not perhaps the easiest thing to do. My last couple loads I used the chronograph method looking for flat spots within a group of incrementally higher charges (I used 1%). Some of my reading suggests this is flawed simply because it ignores the inevitable E.S. of a particular load (if 77 grains shoots to the high side of its potential extreme spread, and 77.7 goes to the low side if it's respective spread a false reading results if I understand the arguement against this method).

I just reread Mr. Newberry's OCW method, and to my mind the method looks to hold some merit for light barreled guns. Is there anything else I should be considering or am I perhaps over thinking things?

 

[lawman29]

The most important thing to load development is to have a "process * method * formula". No shotgun approach... You'll have success with whatever method you choose.

 

[Toby Bradshaw]

For my Remington 700 in .300 Winchester Magnum with 180gr Barnes TSX, I did a ladder test at 100 yards from 73.7gr to 78.2gr H4831SC in 0.9gr increments. Based on previous experience with Barnes TSX in other rifles I seated the bullet 0.050" off the lands. Brass was RWS/RUAG, primer WLR. Redding body die and Lee collet neck die, Wilson seater.


I settled on 76.4gr H4831SC in the middle of the node. I cleaned the rifle and shot 2 foulers at 200 yards (fouler 1 isn't shown, fouler 2 is on target 5 at in the 6-ring at 9 o'clock). Shots 3 and 4 (target 5) were touching. Scope (Leupold 4.5-14x56) adjusted to center the group, then fired shots 5 (target 4), 6 (target 3), and 7 (target 2) to confirm zero.



Seemed to work OK when I took it to Namibia.



For big boomer hunting rifles the load development process need not take many rounds. I've never used more than 20 shots.

Edit: I guess I should add that I don't shoot big game beyond about 325 yards, so I don't test or develop loads with long-range hunting in mind.

 

[JFrank]

Double like

 

[rsmithsr50]

iMHO,
ocw is for two groups of people:
those with more time and money than they know what to do with;
those that do not know how to start from a ladder.

a ladder is quick simple process
10-20 single shots at aprox 300 yards in very small steps.
.2 or .3 (max is 1/100 of case vol)
record each shot on the target ,spotting scope and blank target
evaluate chrono data is helpful.
shoot a couple of 3 shot groups based on ladder,
shoot 1 or 2 five shot groups based on the 3 shot groups
fine tune the best with smaller steps and length
done

 

[Ned Ludd]

Adam - a ladder test and Dan Newberry's OCW test are both fundamentally looking at the effects of barrel timing and barrel harmonics. The main difference between the two is that with Dan's OCW method, you're looking at the effect of charge weight on movement of the centerpoint of a group on the target as opposed to vertical displacement of a single shot as with the Audette Ladder Method. In addition, the OCW Method can be carried out effectively at a distance as close as 100 yd, although it can also be done at longer range. A ladder test is most often carried out at a minimum of 300 yd (or more) for optimal vertical resolution.

Both methods are dependent on barrel timing/harmonics with respect to charge weight and velocity. You're essentially looking for at least two to three successive charge weights where either the movement of the group, or the vertical dispersion of individual shots is at a minimum, indicating a charge weight "window" that has minimal effect on shot dispersion (i.e. good precision). Both methods can be effective, although you will typically find BR shooters concerned with the absolute best possible precision most often, if not exclusively, use the ladder test.

If you're interested in using the OCW approach, Erik Cortina started a thread here some time ago using a variation of the OCW approach that currently has over 100 pages of targets, analysis, and feedback. You may find it of interest:

http://forum.accurateshooter.com/threads/long-range-load-development-at-100-yards.3814361/

 

[Ralph Littlefield]

iMHO,
ocw is for two groups of people:
those with more time and money than they know what to do with;
those that do not know how to start from a ladder.

a ladder is quick simple process
10-20 single shots at aprox 300 yards in very small steps.
.2 or .3 (max is 1/100 of case vol)
record each shot on the target ,spotting scope and blank target
evaluate chrono data is helpful.
shoot a couple of 3 shot groups based on ladder,
shoot 1 or 2 five shot groups based on the 3 shot groups
fine tune the best with smaller steps and length
done

Perhaps a third type would be those that do not have easy access to a 300 yd range? Can a ladder test be effectively done at 100 yds?

 

[Depart123]

You will find lots of Audette ladder elitists on here. A few posts above is just one example. When properly done and read (both important qualifiers), each give you similar information and with about the same number of rounds.

Audette method proponents always talk about just needing single shot ladders, but then in the same breath talk about fine tuning and confirmation. So the number of rounds fired between the two, usually ends up being within a few rounds of equal.

Barrel harmonics are at play in either method. Not only is velocity climbing, but the barrel is moving up and down as well. This causes some overlap in the pattern when done vertically as in the Audette ladder. In the OCW you see this as well, but since the groups are side by side, it is somewhat easier to read.

When the OCW is fired from left to right, with the points of aim in a straight line, and the point of impact is offset into one of the 4 quadrants (ex. 2moa up and 2moa right from point of aim), then you not only get to see the rise and fall of the groups, but thier clock position changing relative to point of aim as well.

If you draw a line from the center of one group to another, then another line from that center to the point of aim, you get a more comprehensive picture of what exactly is going on.

This is a test done with the same number of shots as an Audette ladder, but done in an OCW format:

The pattern of barrel movement is obvious, and groups (single rounds in this case) can be easily compared side by side on 2 axes rather than just one.

Edit: As a side note, the 41.4 charge was chosen because of both the similar height and clock position of the POI to POA between 41.2-41.6.

This load discovered by OCW, proved itself by the numbers as well. It was proved in a 4x5 grouping test, at the same POA at 200 yards, that measured under .75 moa for all 20 shots.

It has been shot a couple hundred times at a 12" steel plate at 910 yards as well, in both summer and winter, and has proved extremely reliable.

 

[JFrank]

That’s definitely a good way to test , as well as other methods. I personally struggle with them whereas Brett is very good reading them. I don’t think there is one absolutely superior to the other just in the eye of the tester

 

[CharlieNC]

I personally like a two shot ladder at 200yd. Two shots because with a single ladder, one bad shot can ruin the ability to get a clear interpretation. 200yd because the desired changes are magnified significantly vs 100yd, but the distance is not enough for ambient conditions to have an overbearing influence. As mentioned these methods are all about harnessing the benefits of barrel harmonics (vibration), and consequently I have never seen enough data to convince me that a "flat spot" based on velocity has any validity.

 

[mgunderson]

There are many methods to end up with a good load. Try them all! Testing is fun and I generally learn something in the process.

Test until you are happy! Personally, I like to test at distance. IME some of the groups that look good at 100 don't look good at 300 or 600.

 

[group therapy]

You will find lots of Audette ladder elitists on here. A few posts above is just one example. When properly done and read (both important qualifiers), each give you similar information and with about the same number of rounds.

Audette method proponents always talk about just needing single shot ladders, but then in the same breath talk about fine tuning and confirmation. So the number of rounds fired between the two, usually ends up being within a few rounds of equal.

Barrel harmonics are at play in either method. Not only is velocity climbing, but the barrel is moving up and down as well. This causes some overlap in the pattern when done vertically as in the Audette ladder. In the OCW you see this as well, but since the groups are side by side, it is somewhat easier to read.

When the OCW is fired from left to right, with the points of aim in a straight line, and the point of impact is offset into one of the 4 quadrants (ex. 2moa up and 2moa right from point of aim), then you not only get to see the rise and fall of the groups, but thier clock position changing relative to point of aim as well.

If you draw a line from the center of one group to another, then another line from that center to the point of aim, you get a more comprehensive picture of what exactly is going on.

This is a test done with the same number of shots as an Audette ladder, but done in an OCW format:View attachment 1150007

The pattern of barrel movement is obvious, and groups (single rounds in this case) can be easily compared side by side on 2 axes rather than just one.

Edit: As a side note, the 41.4 charge was chosen because of both the similar height and clock position of the POI to POA between 41.2-41.6.

This load discovered by OCW, proved itself by the numbers as well. It was proved in a 4x5 grouping test at the same POA, at 200 yards that measured under .75 moa for all 20 shots.

It has been shot a couple hundred times at a 12" steel plate at 910 yards as well, in both summer and winter, and has proved extremely reliable.

is this a sine wave test?

 

[Depart123]

There are many methods to end up with a good load. Try them all! Testing is fun and I generally learn something in the process.

Agreed. Problem is, people get emotionally invested in something and defend it to absurdity.

These types have finished learning. You won't persuade them one bit. You could absolutely destroy thier position with evidence and logic one day, and they would answer another thread the next day with the same diatribe.

 

[Depart123]

is this a sine wave test?

It shows a sine wave to be sure, which is one of the points I was getting at.

It is simply an OCW type format, but with single shots. I only did it that way to contrast with the single shot Audette ladder. I wouldn't typically do it this way.

 

[rsmithsr50]

SORRY THE TIME AND COST OF OCW is more than a simple ladder. always has been always will be.
ocw users always try to justify wasting time and money.

You will find lots of Audette ladder elitists on here. A few posts above is just one example. When properly done and read (both important qualifiers), each give you similar information and with about the same number of rounds.

Audette method proponents always talk about just needing single shot ladders, but then in the same breath talk about fine tuning and confirmation. So the number of rounds fired between the two, usually ends up being within a few rounds of equal.

Barrel harmonics are at play in either method. Not only is velocity climbing, but the barrel is moving up and down as well. This causes some overlap in the pattern when done vertically as in the Audette ladder. In the OCW you see this as well, but since the groups are side by side, it is somewhat easier to read.

When the OCW is fired from left to right, with the points of aim in a straight line, and the point of impact is offset into one of the 4 quadrants (ex. 2moa up and 2moa right from point of aim), then you not only get to see the rise and fall of the groups, but thier clock position changing relative to point of aim as well.

If you draw a line from the center of one group to another, then another line from that center to the point of aim, you get a more comprehensive picture of what exactly is going on.

This is a test done with the same number of shots as an Audette ladder, but done in an OCW format:View attachment 1150007

The pattern of barrel movement is obvious, and groups (single rounds in this case) can be easily compared side by side on 2 axes rather than just one.

Edit: As a side note, the 41.4 charge was chosen because of both the similar height and clock position of the POI to POA between 41.2-41.6.

This load discovered by OCW, proved itself by the numbers as well. It was proved in a 4x5 grouping test, at the same POA at 200 yards, that measured under .75 moa for all 20 shots.

It has been shot a couple hundred times at a 12" steel plate at 910 yards as well, in both summer and winter, and has proved extremely reliable.

 

[JFrank]

SORRY THE TIME AND COST OF OCW is more than a simple ladder. always has been always will be.
ocw users always try to justify wasting time and money.

Correct me if I’m wrong but you seem to be discouraging one method while promoting another.
Is that a fair assessment?

 

[dsculley]

The main benefit of the OCW over the ladder is, as was said earlier, a single thrown shot can lead to misinterpretation/wrong results. An OCW doesn't really require that many more shots than a ladder. There is enough information available today that you should know ahead of time about where you will wind up with a particular powder/primer/bullet make/bullet weight combination. You only really have to test a narrow window to find the best load, you don't have to test a 3 gr spread in .2 gr increments. You can go to Dan's practical rifle forum if you want to get feedback from Dan himself. You can go to BangSteel.com and contact him if you want his help in load development. You will find that he is very knowledgeable and helpful.

I personally don't like the chronograph method because I have never found that my target and my chronograph always agree on the "best load". For me, the target will always be the final arbiter.

 

[Bc'z]

SORRY THE TIME AND COST OF OCW is more than a simple ladder. always has been always will be.
ocw users always try to justify wasting time and money.

My time, my money.
I'll spend it as I see fit.
If a guy wants to shoot groups in a ladder or OCW test that's his choice.
It's blatantly obvious you like the Audette ladder method.
So when your done shooting your test, do you simply settle in on a charge weight, or do you now move to 5-10 round groups to confirm and then move to seating test?
Not being argumentative..
Asking simple questions why you feel one method is far more superior to another.
It's my belief it really doesn't matter how you get there, just so long as you get there, and learned something and had fun in the process!

@Meangreen beautiful target, alot of info can be gleaned from that format of a OCW test.
I think I'll give it a try, and see if I can save myself a few bucks.

 

[mike a]

iMHO,
ocw is for two groups of people:
those with more time and money than they know what to do with;
those that do not know how to start from a ladder.

a ladder is quick simple process
10-20 single shots at aprox 300 yards in very small steps.
.2 or .3 (max is 1/100 of case vol)
record each shot on the target ,spotting scope and blank target
evaluate chrono data is helpful.
shoot a couple of 3 shot groups based on ladder,
shoot 1 or 2 five shot groups based on the 3 shot groups
fine tune the best with smaller steps and length
done

20 single shots on the ladder, then a couple 3 shot groups 6+20=26 then 1 or 2 five shot groups 10+6+20=36, then ( fine tune with smaller steps and length ). I'm just counting to analyze if I have enough time and money to do it your way. Mike

 

[daniel brothers]

Quote... I'm just counting to analyze if I have enough time and money to do it your way. Mike

LOL... that just depends on how accurate you want it to become.

Time and money means nothing to a Race Car Driver... or a Bench Rest Competition Shooter....... they are above the normal average Guy who will settle for less than maximum perfection.