Ladder V's OCW: Which works best for you?

[VarmLR]

 Interested who else uses the OCW method to determine the least pressure sensitive plateau adjusting seating depth for grouping.

I'm asking the question because at my last range outing there were a fair few people ladder testing using 3 shot "groups" which is something that bemuses me as longer run it tells very little about the load except approx' POI.  Upon asking one chap, the response was "I don't ever shoot more than 3 and often just shoot 2 as it gets silly and expensive".  I get the expense but that is a reality of load development.  I don't get the logic of shooting a few.  I mentioned this on another shooting forum and would be interested to poll results here to see how opinion differs from a more LR dedicated crowd.

I hold my hands up and say that I'm a recent convert to the OCW method as it just seems to work and using half the ammo to get there.  I can typically get a rough load within 21 rounds (3 sighters plus 6 groups of 3 for POI), then I usually load up 3 sets of 5 at the middle of the optimum range to confirm groups and MVs.  If needed, I then alter seating depth, usually in 10 thou jump intervals, to fine tune the harmonic.  Using the ladder system, I used to load (typically) 5 rounds at each charge across about 6 or seven charges, then play with seating if needed.  35 rounds V's 21.

[onehole]

OCW and  fine tune charge at 200,,,,,,,,not convinced seating depth should be a secondary necessity at all,,,,,I like to be close to lands and then just OCW to it,,,,,,,,never had a problem,,,,,,just my way and I pay heed to the secrets and findings of the "Houston Warehouse",,,,,makes a lot of sense. In addition unless you are almost anal in your approach to a consistent and repetitive reloading regime you will fail,,,,O

[bsbxl]

I would be interested to know if there have been controlled tests of those methods (OCW, ladder, ...)? For example, if you did the procedure (OCW or ladder) five times in a row, would you end up with the same end result each time?

[VarmLR]

I don't know the answer to whether there's been controlled tests I've found after changing primer type, re-doing the OCW tests resulted in much the same result but with better ES.  It would be interesting to do though, if expensive on powder and bullets.  Given that components are all of the same batch, I couldn't see any reason for repeating it unless a significant change in temperature (eg summer to winter) takes place.

One thing's for sure and that's with ladder tests, because the group size shot is rarely representative you wouldn't always know if you were on the edge of a node or smack bang in the middle, at least not without shooting large strings.  At least with the OBT or OCW tests, you can pick the node point which gives a better chance of being pressure tolerant. When changing to a new batch of powder, it's possibly worth re-doing the OCW as it doesn't involve too many bullets. At least you'd get a feel after a while with the powders used if it was worthwhile doing this or not.

[srvet]

Has anyone tried the 10 round load development method as in this YouTube video? 

https://youtu.be/ACyfeeBHVOA

 

 

 

[VarmLR]

I'll be trying that for the first time next week and comparing the outcomes with OCW.  In theory, they ought to be the same, because you also note ES/velocity for OCW as well as fall of shot.  In practice, I feel more comfortable seeing the fall of shot comparisons, even though the physics does stack up for the 10 shot OBT.  The thing I have against it is that it relies upon there being no fliers to the loaded rounds in terms of ES.  You have to be very careful to ensure almost perfection on loading if you are to rely on the results with confidence.

 

(had a chuckle at the moan about bullets costing "..40 Cents apiece..." in that video)

[hunter686]

On 18/02/2018 at 11:41 AM, srvet said:

Has anyone tried the 10 round load development method as in this YouTube video? 

https://youtu.be/ACyfeeBHVOA

 

 

 

I use this method to great effect. My current match round was picked up in the very first test (about 10 rounds) and I havn't changed it 700 shots. Apart from to chase the lands. I'm looking for to 1/3 MOA out that gun to 1000 yards 

[Cienfuegos]

According to my experience with 308w, 6.5x47 and 7 SAUM cartridges. Both systems are good depending on what. For short-distance competitions + -300 meters, PRS or hunting, the OCW system is fast and efficient because the repetitiveness of the point of impact on the target is important ... it is against the shooter must be sub moa, to ensure A compression of the results. While the stair system is absolutely objective to what is being tested. And the definitive long-distance method, where a good homogeneity of the SD and the ES is important for the projectile to fly the same way every time.

[Popsbengo]

We debated this a while ago and no doubt again in the near future!  Of course barrel harmonics are well understood and an optimised charge will result in better accuracy, it's just how one arrives at that.

What works is a matter of opinion and that's worrying from a scientific point of view.  The inferences drawn from exceedingly small samples with ever changing conditions (in the barrel) and extremely accurate measuring of charge weights (that vary with humidity) leaves many of the techniques that rely on just a few rounds very suspect from a statistical point of view.

I guess it's how much money your have, how much useful life you want to take from your barrel. How many unicorns you can see in velocity readings (from less than perfectly accurate chronos) is a particular bug-bear,  ridiculous claims of "flat spots" on charted data - I'd have more faith if it was repeated >5 times with exact conditions resulting in good matches of data.

If one goes to all this apparent bother then it's implicit to re-do tests every time a new batch of primers/bullets/powder is used.

Well, that's my opinion, just as valid/invalid as the next !😉

[Popsbengo]

On 2/16/2018 at 11:12 PM, bsbxl said:

I would be interested to know if there have been controlled tests of those methods (OCW, ladder, ...)? For example, if you did the procedure (OCW or ladder) five times in a row, would you end up with the same end result each time?

👍👍

[Popsbengo]

On 2/23/2018 at 8:46 PM, hunter686 said:

......... Apart from to chase the lands. I'm looking for to 1/3 MOA out that gun to 1000 yards 

thereby reducing the starting pressure in your round so invalidating the whole procedure?

[The Gun Pimp]

On 2/23/2018 at 8:46 PM, hunter686 said:

I use this method to great effect. My current match round was picked up in the very first test (about 10 rounds) and I havn't changed it 700 shots. Apart from to chase the lands. I'm looking for to 1/3 MOA out that gun to 1000 yards 

One-third MOA at 1000 yards!  Good luck with that - this year, in the UKBRA 1000 yd Championship, I would estimate that around 700 5-shot groups were shot - no one got a 1/3 MOA group!  Please bring your rifle along to one of our shoots and clean-up!

[Popsbengo]

11 minutes ago, The Gun Pimp said:

One-third MOA at 1000 yards!  Good luck with that - this year, in the UKBRA 1000 yd Championship, I would estimate that around 700 5-shot groups were shot - no one got a 1/3 MOA group!  Please bring your rifle along to one of our shoots and clean-up!

😂😉

He did say he was "looking for ..it"  not achieving it!    I'm looking for 1/2 moa at a mile but so far......

[Re-Pete]

I'm happy with 1 MOA at 600yds on a windy day................

Pete

[Brillo]

I shoot several 3-round groups, going up in 0.2 grain intervals, starting with one that give pMax of 56,000 psi, up to maximum pressure predicted by Quickload.

Before I hear a lot if sucking of breath and “ tut, tut you can’t trust Quickload,” let me confirm that I have successfully tweeted the parameters of all the powders I’ve used, for barrel twists from 1:8 to 1:12 based on observations and measurements over a lot of rounds shot, and I mean a lot.

Using my calculations and Optimum Barrel Times I can generally get to a node quite quickly and I’ve found, again through experience, that 56,000 psi is a known good starting point.

Just by way of experiment I tried ladder testing but the POIs are too close at 200 yards to give good results (200 yds is my home range max distance).

[Popsbengo]

49 minutes ago, Brillo said:

I shoot several 3-round groups, going up in 0.2 grain intervals, starting with one that give pMax of 56,000 psi, up to maximum pressure predicted by Quickload.

Before I hear a lot if sucking of breath and “ tut, tut you can’t trust Quickload,” let me confirm that I have successfully tweeted the parameters of all the powders I’ve used, for barrel twists from 1:8 to 1:12 based on observations and measurements over a lot of rounds shot, and I mean a lot.

Using my calculations and Optimum Barrel Times I can generally get to a node quite quickly and I’ve found, again through experience, that 56,000 psi is a known good starting point.

Just by way of experiment I tried ladder testing but the POIs are too close at 200 yards to give good results (200 yds is my home range max distance).

Pretty much what I do.  I use Quickload too, saves some time and money.  I do 0.5gn steps for .338 as it's around +90gn!

Problem with grouping at greater distances than 200 is wind effects  - muzzle jump and windage (yes, I know muzzle jump happens near to the muzzle!) .  200yds does give a better result for me when developing both .308 and .338 - the grouping performance seems to carry-over to long ranges better than 100yds.

[No i deer]

I group test some ammo for my new 1 in 8.25 saum barrel.

The loads that grouped the best I chronied,one was 61.5grs the other 61.9grs. The 61.5gr load shot 6fps ES and the 61.9gr shot 26fps.

I then tried a ladder test at 305yds.

I loaded up starting at 60grs going up in 0.1gr increments up to 62grs, after 8 shots the load plateau'd through the next 12 shots before the shots started climbing and showed a faint ejector mark at 62grs.the plateau of the 12 shots gave a verticle spread of 0.687 of an inch....

I already tested accuracy and chronied and the 61.5gr load was near the middle of the plateau so I went with this as there a little wiggle room for temperatures variations...

The load shoots great and driver error is the weak link 🙄😁

[No i deer]

7 hours ago, The Gun Pimp said:

One-third MOA at 1000 yards!  Good luck with that - this year, in the UKBRA 1000 yd Championship, I would estimate that around 700 5-shot groups were shot - no one got a 1/3 MOA group!  Please bring your rifle along to one of our shoots and clean-up!

😁🤣😂🤞😉

[VarmLR]

After trying the Satterlee method several times for my .223 with similar results (not the same but similar) they didn't replicate the nodes found using OCW that well so I can only conclude that even if you could get consistency into the method and take great care, OCW seems more reliable at determining where barrel harmonics are at wrt to nodes, then ES/SD can be examined for various nodes to pick a load.  More economical for me than the ladder method given I shoot 5 shot strings for each load. 

 

I'd be delighted with 1/2 moa at 1000 yds...in fact 3/4 moa would be great with a factory rifle at that distance!  1/3 moa at 100 yds even with laser guided bullets is a big ask 😄

[baldie]

I tried the Satterlee method, for the first time last week on a .260 Ackley Improved for myself.

It works. Testing 0.010" off the lands for safety, as I knew the load was near maximum, I got a plateau , and worked from the middle of that. Good SD, and ES..

To tighten the load, i went deeper into the case, with little effect.

I then went onto the lands, and one holes.

Could have actually developed that load completely, in 15 rds.

[ds1]

OWC or Ladder - for me about as effective as trying to herd cats. What I mean is whatever results you get one day will change when temperatures change ( ok a bit extreme here, I shoot over a year from -20c to +35c) but changes in temperature will effect at least 5 things, primer ignition, powder burn rate, expansion / contraction of barrel, case and bullet friction. All of which will change barrel harmonics. I don’t even think it’s as simple as adding/ reducing powder to maintain a specific velocity. 

So unless you only shoot within a given (small) temperature range how useful / repeatable are the results? 

[Popsbengo]

2 hours ago, ds1 said:

OWC or Ladder - for me about as effective as trying to herd cats. What I mean is whatever results you get one day will change when temperatures change ( ok a bit extreme here, I shoot over a year from -20c to +35c) but changes in temperature will effect at least 5 things, primer ignition, powder burn rate, expansion / contraction of barrel, case and bullet friction. All of which will change barrel harmonics. I don’t even think it’s as simple as adding/ reducing powder to maintain a specific velocity. 

So unless you only shoot within a given (small) temperature range how useful / repeatable are the results? 

100% agree.  statistical phantoms

[VarmLR]

On 10/27/2019 at 9:56 AM, Popsbengo said:

100% agree.  statistical phantoms

I have a difference of opinion, at least where OCW is concerned.  It reaches the same end point as your QL optimum barrel time method in as much as it finds the optimum harmonic node for your barrel.  Whatever method you choose will be open to the variability of temperature change as the temperature doesn't care what method you choose!

OCW in theory should work and it has obviously worked for baldie but it won't for everyone.   I think it requires far more batch consistency than most are willing to admit wanting to prepare.

[ds1]

Without wishing to go off topic I think the point is that temperature affects barrel node in several ways so you get a ballpark solution with either of the 2 methods.

The nearest thing that I have to a br rifle is a Sako Finnfire Range 22lr. It has a diet of Eley Tennex - same lot number ( from one machine) - most would consider it fairly consistent ammunition. If I shoot it on my range over a year then group sizes at 50m vary from thumb nail size to little finger nail size. This is overall temperature effect I think. I can tune it on a given day by using a barrel tuner..... but that is it. I would also argue that centre fire BR shooters use similar practices with the black art of clicking a Harrell powder thrower to tune the load on a given day rather than using a barrel tuner.