New 6.5 ocw results

[LongRange]

i never had any issues with it...its not H4350 but it is about as close as you can get...IMR has the new 4451(i think)that is supposed to very temp stable...im going to have to get a lb of it and work up a load now and then shoot the same load when its 90degs here.

[doctnj]

I bought some additive for my tumbler. I don't like it in the least. The brass comes out clean. It just has kind of a matt finish not a high shine like the media by itself. I think Im going to scoop out about half if not all and add some new media and never use that stuff again. I think its just a polishing paste. The problem is the paste puts a film on the media so the rouge on the shells are deactivate by being coated. Maybe I put too much in but Im pretty certain its at least close. I think if you are using plain media w/o rouge in it then this might be an improvement. But also by coating the media it sticks inside the cases A LOT more. No likey!!

[doctnj]

UPSLIDE; Here is the course test. I also think 41.8 was quite acceptable as they are on a good horizontal with a bit of wind shift. I know wind isn't supposed to effect 100yrds but it was blowing fairly good that day. 42.5 looked pretty promising. So from about 41.8 up to 42.5 were all pretty close. So that is my "node" I just chose to explore the upper end of it. I hope this picture makes more sense to you now. The squares are 1/2". The low shot on 42 was a shank.

[LongRange]

all those loads with the exception of 42.3 43 and 43.5 look like they could be tuned with seating depth.

[yobuck]

Excuse me for asking, but as they say inquiring minds need to know. Lots of things have changed over the many years
since i started reloading ammo. Some of which is terminoligy in the way we describe things. I think we can all agree that
the reason most of us reload ammo, is so that we can get the best performing ammo for our particular guns.
The term node for example comes to my mind. I cant recall that term being used except for very recently, meaning a few years at most.
Im not debating its merit, but simply a better understanding of it. In my looking at the target presented here by Docnj, my natural thought
process looks at each group. Being a velocity person, i want the best group with the best velocity i can get. So my eyes went immediatly to
the 43.3 group. I personaly would be loading 5 more and seeing if i could duplicate that performance. But obviously that isnt the same thought
process others here have, and im wondering why? Another reason for my curiosity is, that over the years ive noticed numerous times when
increasing powder charges in small increments, the groups remain in the same place on the target even with a grain or more difference in charge weight.
We can even see that on this target, which to some degree at least might explain the term node? But does it also say then that precisly weighing charges isnt necessary once a load is established?

[upSLIDEdown]

Personally, I think I'd shoot the ocw again. From 41.8 up to at least 43. Usually there is a low node and a higher one, but sometimes the high one is too high. LongRange is right, they all look great and tunable. With ocw though, you're looking for poi of the group centers being in the same spot in relation to the poa, not group size. I think you're over the high node, personally. Going off of that target, I would have loaded 42.3. But shooting 41.5 or 41.8 up through 43 or 43.5 again might give better insight. Just keep in mind group size can be tuned with seating depth. What you said earlier was spot on for the ocw test and a 'node'. It's designed so that being a little off on your powder charge won't affect things.

In regards to tumbling, I wet ss tumble now, but in the past I used walnut. I put a few USED dryer sheet strips (usually cut one sheet into 5 strips after they come out of the dryer) to help cut down on dust, and a tiny bit of Nu Finish car polish. Run it for 5 mins first to mix the Nu Finish in, then add the brass.

EDIT: Looks like I replied while yobuck was replying.

Excuse me for asking, but as they say inquiring minds need to know. Lots of things have changed over the many years
since i started reloading ammo. Some of which is terminoligy in the way we describe things. I think we can all agree that
the reason most of us reload ammo, is so that we can get the best performing ammo for our particular guns.
The term node for example comes to my mind. I cant recall that term being used except for very recently, meaning a few years at most.
Im not debating its merit, but simply a better understanding of it. In my looking at the target presented here by Docnj, my natural thought
process looks at each group. Being a velocity person, i want the best group with the best velocity i can get. So my eyes went immediatly to
the 43.3 group. I personaly would be loading 5 more and seeing if i could duplicate that performance. But obviously that isnt the same thought
process others here have, and im wondering why? Another reason for my curiosity is, that over the years ive noticed numerous times when
increasing powder charges in small increments, the groups remain in the same place on the target even with a grain or more difference in charge weight.
We can even see that on this target, which to some degree at least might explain the term node? But does it also say then that precisly weighing charges isnt necessary once a load is established?

Not sure if Dan coined the term 'node' or not, but Dan Newberry's OCW method is where I first heard it.

http://www.ocwreloading.com/

Dan is a good friend of mine, and time and time again, I've seen this method work very well for finding a load. The issue comes into play when people don't follow the directions and target interpretations to a T. The site will explain the concept, so there's no need for me to get into here.

[yobuck]

Well then since he is the person who coined the term, maybe he could come here and explain it to us.
Im sure there would be others besides me who might appriciate it.
Again, i always look for the velocity i want first. Then find ways to keep it by fine tuning the charge and seating depth for the accuracy factor.
Not saying thats the right approach for all applications. But for cartridges wearing a hood ornament like 338 i think it is.

[yobuck]

I did read Dans explanation of the OCW. To me at least it raises more questions over loading opinions than it answers.
In principle i think he's onto something, but which might raise other questions.
Does not the results of the miss match of brass fly in the face of what many here ascribe to?
Does it not also say that powder vollume may be at least equall to pecision measuring as to accuracy?
The 788 Rem by the way was a Rem version of an entry level rifle 40 years ago. I think they cost then about $100.
I bought one in 243 for my now 54 year old son as his first rifle. And i kick my butt that i didnt buy the lefty version
which was a right hand action with the bolt handle on the left side. They have always been known to be a very accurate
gun.

[Robinhood]

Definition of node

4 a : a point, line, or surface of a vibrating body or system that is free or relatively free from vibratory motion


b : a point at which a wave has an amplitude of zero

[doctnj]

Ok Ive been reading everyone's input and staring at the targets and velocity charts and this is what my plan is for better or worse.

1. Im seating the bullets back to 2.200 which is .009 deeper than last test (.028) off lands and hopefully this time will fit in mags well.
2. Trimming the cases back to book "trim to" length exactly instead of leaving slightly long even though chamber will take it
3. Re running test all the way from 38.5 to 42.8 in .3 increments skipping a few of the wild groups but that still leaves 9 charges roughly

Reasoning is:
1. There were some accurate slower groups however neck tension wasnt right so I have to rule those in or out.
2. Pressure signs started showing this last go round in charges that showed none before I left case necks long.
3. I am not going to re test 43.3 because it was isolated and "sticky" not to mention 200 fps above max velocity in the winter.
4. And last reasoning is plain jane off the shelf winchester was extremely accurate at average vel. of 2785 and I want to target that area of the velocity curve.

If from here all pressure is alleviated I can then finally play with seating depth as ALL rounds down range will be done under same condition.

So robinhood that would correlate with the point at which the end of the barrel is on the x axis neither rising nor falling.

[upSLIDEdown]

Definition of node

4 a : a point, line, or surface of a vibrating body or system that is free or relatively free from vibratory motion


b : a point at which a wave has an amplitude of zero

This. lol

Ok Ive been reading everyone's input and staring at the targets and velocity charts and this is what my plan is for better or worse.

1. Im seating the bullets back to 2.200 which is .009 deeper than last test (.028) off lands and hopefully this time will fit in mags well.
2. Trimming the cases back to book "trim to" length exactly instead of leaving slightly long even though chamber will take it
3. Re running test all the way from 38.5 to 42.8 in .3 increments skipping a few of the wild groups but that still leaves 9 charges roughly

Reasoning is:
1. There were some accurate slower groups however neck tension wasnt right so I have to rule those in or out.
2. Pressure signs started showing this last go round in charges that showed none before I left case necks long.
3. I am not going to re test 43.3 because it was isolated and "sticky" not to mention 200 fps above max velocity in the winter.
4. And last reasoning is plain jane off the shelf winchester was extremely accurate at average vel. of 2785 and I want to target that area of the velocity curve.

If from here all pressure is alleviated I can then finally play with seating depth as ALL rounds down range will be done under same condition.

So robinhood that would correlate with the point at which the end of the barrel is on the x axis neither rising nor falling.

I think this is a good idea, except for leaving things out. If they're on one end or the other, that's fine I guess, but I definitely wouldn't leave anything out in the middle of the range.


I'll shoot Dan a message and get him to get in here if possible. I think he's a member here, because when DrThunder went up to Bangsteel, he made his way over here for a short spat.

[doctnj]

The charges Im leaving out were verified on two tests to be spread quite a lot. I hope to not be leaving any meat on the bone but going by past experience, it took nearly 4 hours to shoot 100 rounds during a test. Its not intermittent charges spread all over but a small batch in a row that were poor performers with quite a vertical spread.

[DanNewberry]

Okay, thanks for the invite, Bryan. :)

I did look at the targets, and I do think he's on the high node in the 42.7 grain area. I would say the lower node is at 41.4 to 41.5 grains. Hornady used to put 41.5 grains of H4350 on the original boxes of the 140 grain AMAX CM ammo. I don't believe they're doing that these days. But speaking of Hornady, they're almost certainly reason number 1 that H4350 is hard to find. We reloaders really just take up a tiny portion of the powder market; the big ammo makers use the majority of it. I believe they're using a lot of Varget too.

I'm not an engineer, and I've never played one TV. :/ But Chris Long, a friend from Washington state is an engineer with some great credentials. He has identified the real reason an OCW load works. It has to do with the acoustic shock wave that runs end-to-end on the barrel after the shot is touched off. This wave moves at the speed of sound in steel, around 18,000 fps. So it turns around a couple times in most rifles before the bullet reaches the muzzle.

You want the bullet to exit the muzzle when this shock wave is away from the muzzle, preferably as far as possible (back at the chamber end of the barrel).

The actual vibration pattern of an individual barrel will be different. If you "rang" the barrel like a tuning fork, one would sound different than the next. Identical barrels may even have a subtle tonal difference, because of the molecular differences in the steel.

So how can different barrels shoot the same load recipe so well? Hornady's factory 6.5CM 140 AMAX load is the benchmark for Creedmoor chambered rifles. If your rifle won't shoot that factory recipe, there is probably something wrong with the rifle. Even though one rifle may have a thin 22" barrel, and another may run a heavy 26 incher, both guns shoot this load very well. Chris Long believes, and I agree, that it is the shock wave's behavior in relation to the barrel time of the bullet (research OBT, Chris Long's system for using Quick Load to find Optimum Barrel Times). There is a bit of room for latitude in the barrel's actual length when identifying a true OCW load. A true OCW load (my terminology) will shoot very well in rifles with various length barrels, say from 20" to 26" or even longer. Apparently this shock wave's end-to-end cycle timing still allows the bullet to leave the muzzle when the wave isn't near the muzzle.

The question would (or should) then arise: "Then OCW loads should shoot the same velocity from barrels of the same length, right?" And I will admit, it has puzzled me for some time as to why these load recipes in fact do not necessarily shoot the same velocity from same length barrels--even though they do shoot very well in the fast and slow barrel. Federal Gold Medal match 308 Winchester ammo almost always shoots great in pretty much any 308 you want to run it in. But two 24" 308 barrels might show 100 fps of velocity difference between them with the same lot of ammo. This obviously means that the bullet is accelerating faster in one barrel than the other, and the barrel time (amount of time the bullets spends in the barrel after primer light) is shorter on the faster barrel. So how does the "shock wave" timing theory accommodate this? Shouldn't one barrel shoot *better* than the other? Yes, one barrel in fact probably will shoot better than the other one. The slow one could group better than the fast one, or vice versa.

An aside: Another thing to consider, often over-looked, is that bullets may accelerate at different rates in different barrels. Like two drag race cars that cross the finish line at different times, but at the same speed. This fact makes it futile to load for a particular velocity in *your* barrel, and expect the same accuracy level that your friend is getting at that same velocity in his barrel.

A good rifle barrel, mounted in a good system (receiver, stock), and fired by a good shooter, will group tight even on what I call "scatter nodes" or anti-nodes. I view targets for clients all the time where I have to really look closely to see where the scatter node is (the scatter node, by the way, is the point along the powder charge continuum where the bullet is leaving the muzzle with the shock wave *at* the muzzle). Accuracy is always the worst at the scatter node.

In the end, however, it doesn't matter if the shock wave theory is a perfectly accurate analysis or not. The facts are undeniable that groups open and close along the powder charge continuum, like ebbing and flowing tide. These accuracy nodes (OCW nodes) are spaced about 3 percent apart ordinarily. The scatter nodes are spaced right in between them, normally 1.5% away from the OCW nodes below and above. This has even held true for the 50 BMG, with around 215 to 230 grains of powder. Nodes are still 3% apart.

For 140s in the 6.5CM, you'll get longer brass life and fewer surprises if you run it somewhere in the 2700's. Yes, they'll shoot well over 2800 fps if you feed them enough powder... and 308's will shoot 175 SMK's to 2750 and faster too. But brass life is very short. With fresh brass, it's often hard to really know that pressures are excessive just by looking at teh cases. The appearance of the primers can be misleading in either direction. Fresh brass of good quality is very resilient, and can take the "heavy hit" for first firing, and perhaps for one or two more. But the effects of the high pressures will soon be evident if you try to keep using the brass. Sticky bolt lift can come with the same load, same powder lot, same outside temperature--with nothing changing other than it's the second or third firing of that brass case, which is no longer able to sustain the chamber pressures and "snap back"; it's been over-worked.

I don't have much time to proof-read this... so excuse the typos where you find them. :)

Dan

[doctnj]

Wow Dan, thanks for taking the time to give your input. I am sooo glad you mentioned those two node areas. They are precisely where I broke my next test apart to rerun both areas with more emphasis on the lower for obvious reasons. Will be shooting it Sunday although it will be super cold. I am obsessed to narrow this down!

[upSLIDEdown]

The charges Im leaving out were verified on two tests to be spread quite a lot. I hope to not be leaving any meat on the bone but going by past experience, it took nearly 4 hours to shoot 100 rounds during a test. Its not intermittent charges spread all over but a small batch in a row that were poor performers with quite a vertical spread.

Again though, OCW is NOT about group size. It's about the same poi in relation to the poa for a string of charge weights. You can't go by the group sizes.

[yobuck]

Thanks Dan for taking the time to come and explain your theory. I hope to stop by your place in the near future and meet you.
I think probably due to my age it will be difficult for me to totaly unlock my mind to some things.
Its fine to say dont look at the group, but what are we trying to accomplish to begin with?
Does that mean that the very good group i shot with my grandsons new Savage 308 right out of the box shouldnt be counted?
Or was i just lucky enough to win the lottery with one ticket? And ill admitt that for me luck always plays a roll.
As for the molecules in the barrel steel, 25 years ago it was believed by those in the know, that the best accuracy couldnt be achieved unless the molecules
in the barrel were all properly alligned, (im not joking). The only way to achieve that was to have a specialist freeze the barrel to some
ungodly low temperature which supposedly alligned the molecules. I sent the barrel of my 30x378 out to be done. Did i notice any difference
after it came back? Well i guess i wasent a good enough shooter to notice it. And i guess not many others were either, because im not aware of
that taking place anymore. Its been widely known for as long as i can remember that velocity and accuracy dont necessarily go hand in hand.
Pick your poisen for what you need to do. There are times when a compromise can be reached with at least satisfactory results, of coarse depending on the individual view of things.
Benchrest matches wouldnt be one of them however. But its my opinion that banging steel at long distances could be.

[DanNewberry]

Thanks Dan for taking the time to come and explain your theory. I hope to stop by your place in the near future and meet you.
I think probably due to my age it will be difficult for me to totaly unlock my mind to some things.
Its fine to say dont look at the group, but what are we trying to accomplish to begin with?
Does that mean that the very good group i shot with my grandsons new Savage 308 right out of the box shouldnt be counted?
Or was i just lucky enough to win the lottery with one ticket? And ill admitt that for me luck always plays a roll.

I understand your question. If you're truly on an OCW node, accuracy should be very good. But there will be places that are outside that node where accuracy might be good for just one session, and then it is not repeatable next time out. So you want both stability of POI (point of impact) *and* a decent group. It may not be the best group of the day, but if it's a reasonable group, sandwiched in between two other reasonable groups which are centered at the same point of impact, then that should be your choice load.

Here is a sample target from some years back which might illustrate what I'm talking about:

[doctnj]

upslide I think you missed the part where I said the ones im skipping over had a large VERTICAL spread. Meaning the poi was not poa. Some were even with poa but about a tenth of a mill to the right. Looking at the entire second 'course' test they all averaged about a tenth mil to right. Probably could have dialed over one click and they all would have basically been centered but I didn't want to change anything from beginning to end. And apparently Dan seem to note the two node areas that I am going to go back and do more research on. So there it is.

[doctnj]

Upslide or anyone else for that matter;

Here is a theory that might put a question mark next to the poi, poa deal. When you are shooting a test what is your rifle zeroed with? More than likely a load that is not an accuracy node. There fore when you zero your rifle originally, it let say hit high and right, so you dial down and left. Now you are center punching the target.


Now you go out to test some loads. You run across a group that punches a size of a dime down and left of bullseye. Oh well that cant be an accuracy node because poi doesn't equal poa right. Maybe wrong! What if that indeed is where the end of the muzzle is truly neutral and your scope was dialed to compensate for less accurate ammunition?

[DanNewberry]

It isn't about where the end of the muzzle is neutral, it's about the location of the shock wave, regardless of which way the muzzle is bent when the bullet is released. Ideally, we believe that the bullet should be released at one end or the other of the vibration cycle, where it is relatively static, about to switch directions and go the other way. Remember, you're aligning your scope with the bullet path, not with the barrel.

[LongRange]

dan...so we are looking for the bullet to exit when the shock wave is closest to the muzzle end of the barrel for best accuracy or when the wave is at the action?

ive read a lot of chris's stuff on this as well as yours but still dont understand when is the best exit time...ive also read that the best exit time is at the highest point of the whip.

[DanNewberry]

Chris says when the shock wave is farthest from the muzzle, which will be a time when the muzzle isn't as "excited" by that wave. It is still vibrating, of course, and even with an accurate load you can see the bullets string out in a line if they are being released when the muzzle is moving quickly from one end of the vibration pattern to the other--but that line is still going to be reasonably tight, even MOA or better. If you do see a load grouping in a diagonal line, it is an easy fix; just change the seating depth by .005" (either longer or shorter) and re-test. The slight seating depth change will alter barrel time slightly, and move the point of release on that vibration pattern (in the drawing I shared on page 3) to one end or the other. If you don't see an improvement, move the seating depth in the other direction. Checking .010" seating depth changes may also be helpful.

[cowtownup]

I've certainly enjoyed reading this thread. I've always looked at barrel vibration as a sin wave and having the bullet leave at either the top or bottom of that wave when the barrel was changing directions was the ideal and hence the node... However, thinking about it in terms of a shock wave moving from one end of the barrel to the other adds to the equation. I'm looking forward to some upcoming load development I've got in mind to try and relating it to what I've learned here..

[doctnj]

I THINK this is a good example of that diagonal pattern concept. If I hadnt of shanked that one shot that would have been a much better looking group but its still at same horizontal. I guess my poi, poa idea is getting off track due to terminology. I just thought that if I zeroed my rifle with ammo that is "unknown" as far as excitation of barrel. There is NO WAY to definitively know if poi shift might not be your TRUE zero. Upslide keeps saying poi and poa is so important and should be the same. I could see that if your sighting ammunition had zero "excitation". What do we/I do after I think ive identified the correct load and it holds together...... re zero my scope to accommodate the slight difference in poi and poa. Now then the next test on the same barrel, the poi and poa should be the same because the speed of sound through that metal of your barrel is basically a constant; and upslides comment would be TRUE. Am I way off base?

[LongRange]

Thanks Dan....I was backwards in my understanding of exit time.