OCW method , my first honest try . Come take a look and help .

[Metal God]

Hello

I was part of another thread a little while back that talked about the OCW method . To be honest I'm a skeptic because I've had many questions that never get answered fully or to my satisfaction .

That said I went ahead and gave it a try .

Firearm

Savage FCP with heavy fluted barrel . Shot using front and rear bag ( not a rest )

Load

308 Win
168gr Hornady BTHP
IMR 4895
LC-12-LR
Fed GMM primers

Charges

41.4----- FPS = 2558 , 2560 , 2598
41.8----- FPS = 2634 , 2565 , 2640
42.2----- FPS = 2628 , 2652 , 2658
42.6----- FPS = 2669 , 2663 , 2673
43.0----- FPS = 2710 , 2695 , 2679
43.4----- FPS = 2675 , 2744 , 2665

I don't like those velocities but I have done other test that show how I hold the rifle could give me some of those swings/numbers . so I'm not putting to much into those velocities right now . Consistent rifle hold has been an issue for me for quite some time . It's harder to see on target but often does show up on the chrono .

Target set at 200yds. Sorry I forgot to adjust my scope so everything is high . I almost adjusted the scope after the first shot but figured that would exclude that group and I did not want to do that . The 42.2gr group had that far right shot called right . Just plain old yanked the shot . Not sure what to do when you know you blew one of the shots ??? Is that a valid group anymore ??



I have the measurements of the centers of the triangles
41.4 is a straight line so I'm not sure where the center is ?
41.8 - 2.340 high x .040 left
42.2 - 2.040 high x .610 right
42.6 - 3.040 high x .520 right
43.0 - 2.825 high x .255 right
43.4 - 3.045 high x .725 right

So what does these targets say to you and where is my OCW ?? My guess is between 42.6 & 43.4

 

[jwrowland77]

Your gaps are too large. You probably skipped over a best load....

What's the ultimate goal of this load?

Try 42 and 42.4.

 

[Metal God]

What's the ultimate goal of this load?

Cheap 500yd to 600yd plinking load . I have lots of 4895 and those bullets are pretty cheap .

Try 42 and 42.4.

Why not EDIT : 42.4 and just start working on seating depth ??

 

[ArchAngelCD]

I agree, you will probably want to try in between some of those charge weights. I would also shoot at least 5 rounds to get an AV for a charge weight.

 

[jwrowland77]

Cheap 500yd to 600yd plinking load . Why not 42.2 and just start working on seating depth ??

I don't start fine tuning a load for 500/600 yards until initial test result in sub-MOA results when I was doing the OCW tests.

If you have access to at least 400yd, and it sounds like you do, try a ladder test. It'll result in quicker, better results using less components.

Ladder test if you don't know what it is, it's one round per charge from min to max. Best to shoot at 400yd or further.

You'll get a accuracy node where you'll have three round (even with different charges, lined up horizontally.

Once you get that, pick the middle load and then fine tune your OAL. It's that simple.

In the fine tuning, you should get 3/4-1/2 MOA results at 400 yards.

 

[Metal God]

Unless someone can explain why .2gr is going to swing this test I have to disagree about the charge weights . I thought the whole point of this is to find a less temperamental spot in the charges . If .2gr is going to change my results then it is NOT a less temperamental node .

The next step is changing seating depth . That can easily cancel out the pressure differences a .1 or .2 grain difference .

I said I'm a skeptic , here's where you all or going to have to explain in detail why this method works by proving my concerns are not valid

 

[Metal God]

If you have access to at least 400yd, and it sounds like you do, try a ladder test. It'll result in quicker, better results using less components.

I don't actually . The furthest is 300yds that I can set targets at . The other range is 960yds but only has steel to shoot at at varying distances ( not target stands ) so the latter test would have to be at 300yds .

 

[jwrowland77]

I don't actually . The furthest is 300yds that I can set targets at . The other range is 960yds but only has steel to shoot at at varying distances ( not target stands ) so the latter test would have to be at 300yds .

300 will work, just rounds will be closer. Easier to tell node at 400+ yards.

 

[jwrowland77]

Unless someone can explain why .2gr is going to swing this test I have to disagree about the charge weights . I thought the whole point of this is to find a less temperamental spot in the charges . If .2gr is going to change my results then it is NOT a less temperamental node .



The next step is changing seating depth . That can easily cancel out the pressure differences a .1 or .2 grain difference .



I said I'm a skeptic , here's where you all or going to have to explain in detail why this method works by proving my concerns are not valid

If you do the ladder load, you won't have to worry about a .1 or .2 grain swing. Since you'll be using the middle load of what your barrel harmonics says it likes.

 

[LiveLife]

308 Win
168gr Hornady BTHP
IMR 4895
LC-12-LR

Lyman #49 states, "Shooters should also stay one to two grains below the listed maximum charges due to the smaller volume of GI brass." and I have followed that recommendation when using LC or other thicker military NATO cases with less internal case volume.

Since you are using military LC headstamp brass, would you consider testing lower powder charges?

What's the ultimate goal of this load?

Cheap 500yd to 600yd plinking load . I have lots of 4895 and those bullets are pretty cheap

With LC brass, 41.5 gr IMR 4895 seems to be a popular load with 168 gr bullet and some use below 40 gr charges for shorter range match loads.

 

[Metal God]

Lyman #49 states, "Shooters should also stay one to two grains below the listed maximum charges due to the smaller volume of GI brass." and I have followed that recommendation when using LC or other thicker military NATO cases with less internal case volume.

I have found that when using LC brass which I do a lot . I often don't get to max published loads with out pressure signs . For me that tends to be sticky bolt lifts first . In this case and the test above . I did not get any pressure signs so I'm thinking I'm good .

 

[Duvel]

No sticky bolt = OK pressures?

 

[Dave P]

"The next step is changing seating depth . That can easily cancel out the pressure differences a .1 or .2 grain difference ."

No - don't bother. Those groups are huge. The rifle can do much better than that, so I am sorry to say that you need more practice at being consistent.

Practice more at breath control, cheek weld, trigger control, etc etc.

Don't bother with load tweaking, until your groups are something approaching 1-2 moa. Thats 5 or more shots per group.

 

[Metal God]

No - don't bother. Those groups are huge. The rifle can do much better than that, so I am sorry to say that you need more practice at being consistent.

Don't bother with load tweaking, until your groups are something approaching 1-2 moa. Thats 5 or more shots per group.

haha those shots are at 200 yards and are right at 1 moa . Couple a bit over and a couple .75 moa or better and although I agree that 5 shots is the minimum to call something a group . The directions for the test are quite clear . 3 shots only .

In my traditional load development I shoot 5 shots per charge then confirm with two 10 shot groups . This method how ever is far from traditional

 

[Duvel]

Apples to oranges, but I have a 10 FCP, and my notes on IMR 4895 behind a 168 SMK was 41.4 was 'outstanding'.

Wouldn't have written that if I was over 3" @ 400.

 

[Metal God]

I did a traditional load development using all the same components except powder . RL-15 was the other . 41.5 gr did well so did 43.5gr .

 

[LiveLife]

With RL15 loads, I think you found two accuracy nodes which is common.

With IMR 4895, you may be trying to identify the higher charge accuracy node but the question is have you identified the lower charge accuracy node? Since you started with 41.4 gr, perhaps not?

With 41.5 gr IMR 4895 and 168 gr bullet being a popular load frequently mentioned for LC brass, why not consider looking for another accuracy node?

 

[Metal God]

The suggested start point of the OCW method is just one of many issues I have with this system . The instructions are to reduce the max charge by 10% then load s few bla bla then start loading three shots at another percentage. That turned out to be 41.4 for this load . Hornady has 35gr as there start load so Dan Newberry's OCW method in this instance completely ignores 75% of all possible loads . That seems odd to me but as the title states . This was an honest atempt at this method so I did not change anything .

 

[LiveLife]

So when you did the initial calculation for the backing away from max charge by 10 percent, did you factor in the smaller case volume of LC brass and reduce the max charge by 1 to 2 grains?

- So with Lyman #49 data, for max charge of 42.5 gr (Remington case), 10% reduction would be 38.2 gr.
And max charge reduced by 2 gr, 10% reduction would be 36.4 gr.

- And with Hodgdon data, for max charge of 44.0C gr (Compressed charge with Winchester case), 10% reduction would be 39.6 gr.
And max charge reduced by 2 gr, 10% reduction would be 37.8 gr.

And keep in mind that not all LC headstamp cases have the same internal case volume.

 

[Wildfire]

An Idea

Been some time now, but back when I worked up loads for mine I fired at 100 not 200. That gave me the edge on wind to see what my loads could do rather than my shooting.
Here is what I did.
168 gr, Nat. Match
BR-2 Primers. {CCI}
42.6 of AA2520. The Camp Perry powder.
I always cut the primer pockets at .132" deep and removed flash hole burrs.
Head space was kept at .002 to .003" max.
Lake City brass. {Ave, about 5 to 6 shots per round.}
I could not do much for the Free bore because the rifle was a Rem. 700 PSS.
Those have a very long throat and were made for extra long bullets.
I learned from an old bench shooter to fire at the smallest dot I could see clearly. It worked.
The load was not a speed freak but was extremely accurate. The 168s would hold around 9" at 1000 yards. Just over 3" at 500. I am sure a better shooter could have done better then I did.

 

[LiveLife]

Here's a thread that discusses case volume difference between commercial and LC brass - http://www.thehighroad.org/showthread.php?t=789812

Remington 56.15
Winchester 55.80
Winchester 54.4
Lake City LR 53.45
Lake City '66 53.00
LC LR 07 52.00
LC 09 52.00

Discussion of case volume vs powder charge - http://www.thehighroad.org/showthread.php?t=798749

No, case weight is not linearly related to case volume.

This article (http://www.thefirearmsforum.com/attachments/reloading-pdf.45471/) is an analysis that proves there is no direct correlation between case mass and volume ... the result was that the newer brass required over a grain less powder to get the same velocity average

 

[Metal God]

bds: I used Hornady's data and I completely understand where you are coming from . I also believe I understand why some say to back off of published max loads when using mil-surp brass .

I how ever don't think it applies here It's because case volume "could" be less in military cases . This can result in peak pressure being achieved with a smaller charge . It's more so of a potential issue the larger the case is .

http://optimalchargeweight.embarqspace.com/

Back away from the maximum charge by 7 to 10 percent, and load one test round with this charge. Add 2% to the charge weight, and load another cartridge with that charge. Load a third test cartridge with the next 2% graduation. You will use these three cartridges for sighters, and more importantly to determine pressure tolerance in your individual rifle.

5. Add another 2% or so to the charge level used in cartridge #3 of step 4, and load three rounds with this charge weight. Add .7% to 1% to this charge, and load three more. Add that same graduation again, and load three more. Continue adding the chosen graduation until you have moved ONE increment above your chosen maximum powder charge.

That's Dan's directions on finding the charges to use . I did this and did not get any pressure signs . The fact I used the max published charge in my test with out pressure signs , says to me reducing the start charge would do nothing but reduce the start charge .

It seems pretty clear the OCW method wants you to get to max pressure by asking you to load one increment past max charge . Because of all that I don't think case volume was an issue in these test

I'd also note that these cases are not the run of the mill LC cases .These are the ones made specifically for long range precision rifles (snipers) . They are likely more like commercial brass and is why I'm using them .

FWIW my three start charges were 39.0gr , 39.8gr , 40.6gr . These were to be shot to be sure I was not already at max pressure when I started . I then went up another .8gr to 41.4gr and started the three shot test .

Wild fire :

I do a lot of case prep . I FL size with Redding bushing dies while using competition shell holders that give me a very consistent .002 bump . uniform flash holes , trim cases , clean necks and primer pockets , weigh each and every charge to .00 while using check weights every time I move up in charge , seat to a consistent Ogive length not COAL with micrometer seating die . All on a single stage press so I can control every stage .

 

[LiveLife]

I'd also note that these cases are not the run of the mill LC cases. These are the ones made specifically for long range precision rifles (snipers). They are likely more like commercial brass and is why I'm using them.

If you note my previous post, newer LC brass (whether LR or NATO cross) seem to have same smaller internal case volume.

LC LR 07 52.00
LC 09 52.00

They are likely more like commercial brass

Are you sure? Many claim they are heavier (~177 gr) with slightly thicker wall/less case volume. Only way to be sure is to measure the internal case volume of your cases.


Point is if you are using LC brass with 52 grain internal volume, your pressure will be higher and your lower charge accuracy node may be at lower powder charges.

These are QuickLoad data from above link for two different case volume loads using same 44 gr charge of IMR 4895 and notice the difference in pressure:

56 gr water case - 50888 PSI 2575 fps with 44 gr IMR 4895 168 gr Nosler BTHP COAL 2.830"

52 gr water case - 60191 PSI 2718 fps with 44 gr IMR 4895 168 gr Hornady BTHP COAL 2.800"

 

[Metal God]

Again I don't see it mattering here . I never hit max pressure so I believe I was in the pocket of what the test is supposed to be in .

I'm in no way disputing that there may be another node at a lower charge . I'd bet money I could find one . How ever I don't believe that's what the OCW method is for .

I guess it should also be noted that Dan is a long range shooting instructor . I believe this was developed with very long range shooting in mind . Keeping that in mind . It would make sense you are looking for a node with the most velocity .

I'm not just trying to find a load . I'm trying/testing the OCW method . I could run a traditional test and find a load in less then 50 rounds but that's not the point here .

I have many questions that make me question the validity of the OCW method


Only 3 shots are going to give your likely groups center/mean ??? No not likely .

The Nodes are to show a less temperamental pressure range for less vertical stringing at longer range as well as temp changes , correct ??? You're not going to see that at 100 yards . I would have shot these at 300 but the wind idea made me do it at 200 .

Dan claims you "may be able to find your load , not node but your final load in as little as 20 shots . I call BS on that . If you read his instructions it becomes obvious that's not likely to happen . Example : lets say I confirmed a node in those test . Everybody says I now start testing again in smaller increments to dial in the node . After that I start working on seating depth . So I'm at 35 shots now , another 15 or 20 to dial in the node then another 20 or thirty in seating depth test . We're pushing 70 shots at that point . No wait I might be changing primers and running more test . I can easily find a fantastic load in that many shots with a traditional load development .

The instructions say start 10% below max charge then load three rounds moving up in increments of a % amount . In my this case that dropped my start charge to 39gr for the three round increment pressure test rounds . I then started the actual node testing at 41.4 . That's all well and good until you see that the start charge in the Hornady manual is like 35gr . How can anyone claim this is an OCW test when the test it self EXCLUDES 75% of the charges you can use right from the get go . What if my OCW is actually in the 38gr to 39gr area ???

If seating depth is SOOOOO important why is it that loads I developed 2500rds ago still shoot great in my rifle . I have not change the COAL but my throat has eroded .070+ . If seating depth is so critical should I not have to chase the throat erosion in order to keep the same accuracy ??

Those are just a couple questions off the top of my head that have not been answered fully or at least to a point they are no longer in question .

How ever just because I don't completely understand it does not mean I can't give it an honest try and see if it works .

 

[LiveLife]

I'm in no way disputing that there may be another node at a lower charge. I'd bet money I could find one. How ever I don't believe that's what the OCW method is for.

I'm not just trying to find a load. I'm trying/testing the OCW method.

Bingo.

When we conduct load development, we generally only change one variable at a time while other "known/verified" variables remain fixed. Otherwise, when questionable results show, we won't know exactly what's causing the results.

I think your OCW test with IMR 4895 was testing two variables at the same time. Had you tested the OCW method with your known RL15 accuracy nodes, I think you would have obtained more usable information to validate the OCW method.

I have many questions that make me question the validity of the OCW method ... Only 3 shots are going to give your likely groups center/mean ??? No not likely.

Only you know your rifle best and will know when something isn't right. With my recent carbine load testing, jmorris sounded like Morpheus from the movie Matrix when questioning the validity of 5 shot groups at 50/100 yards. After some pondering, I agreed (as when is a cluster of bullet holes a group with flyers or the start of a pattern?) and started using 10 shot groups which gave me much more meaningful/usable information that 5 shot groups could not.

If I am going to rely on 3 shots, those shots better be consistent but how do you KNOW that?

The Nodes are to show a less temperamental pressure range for less vertical stringing at longer range as well as temp changes, correct ??? You're not going to see that at 100 yards. I would have shot these at 300 but the wind idea made me do it at 200.

See? Another variable to make you wonder even more if the 3 shot groups give you uncertain results.

Dan claims you "may be able to find your load, not node but your final load in as little as 20 shots. I call BS on that.

Well, only if you can REALLY TRUST those 3 shot groups. If the 3 shot groups are not true reflection of small percentage increase in powder charge but other variables (like wind, etc.) then you'll be relying on inaccurate data.

If you read his instructions it becomes obvious that's not likely to happen . Example : lets say I confirmed a node in those test . Everybody says I now start testing again in smaller increments to dial in the node . After that I start working on seating depth . So I'm at 35 shots now , another 15 or 20 to dial in the node then another 20 or thirty in seating depth test . We're pushing 70 shots at that point . No wait I might be changing primers and running more test . I can easily find a fantastic load in that many shots with a traditional load development .

The instructions say start 10% below max charge then load three rounds moving up in increments of a % amount . In my this case that dropped my start charge to 39gr for the three round increment pressure test rounds . I then started the actual node testing at 41.4 . That's all well and good until you see that the start charge in the Hornady manual is like 35gr . How can anyone claim this is an OCW test when the test it self EXCLUDES 75% of the charges you can use right from the get go . What if my OCW is actually in the 38gr to 39gr area ???

That's kinda what I have been trying to say in my previous posts.

If seating depth is SOOOOO important why is it that loads I developed 2500rds ago still shoot great in my rifle . I have not change the COAL but my throat has eroded .070+ . If seating depth is so critical should I not have to chase the throat erosion in order to keep the same accuracy??

I think many do exactly that.

How ever just because I don't completely understand it does not mean I can't give it an honest try and see if it works.

I agree. I am doing the same with the notion of transonic effect on carbine load accuracy as many claim transonic effect on bullet is radial and won't effect much on accuracy but I am seeing the accuracy difference on target between supersonic and subsonic loads using the same bullet.

Ultimately, it's the holes on target that matters. If the groups continue to shrink and remain small, then you must be doing the right thing. If the groups don't shrink, then your process/method is in question.