New 6.5 ocw results

[upSLIDEdown]

To address your first point. This is about the third run on my ocw with this being a fine tune. I ran several at .5 grains and .3 grain spreads already. That is the reason for such small increments. I wanted to watch where it opens up and verify where it was closed. That is why I originally stated that several of the results looked very similar and I only showed one. However the very next load started opening back up. So although this was the tightest group, it was indeed on the edge of the accuracy node. The SD's and ES's of the previous groups were quite similar. Until yesterday, I didnt know what walking a load up at .1 gr increments would look like. Now I do. I could be wrong in my reasoning, however I would think that running such a course test as .5, you could be stepping right over solid gold. Unless you happen to land on that single hole load.

As far as velocity, yes its at the extreme. And I am going to re run with bullets pulled back just to see if there is any additional improvements like drop in velocity and possible tightening of the groups. I would never continue to run a load that displayed signs of high pressure, especially multiple signs. I did clean the chamber last night and even the cases from the tightest group ran through extremely well. I know thats not the same however, when I did this same thing with my 338, the loads that were sticky were still sticky after the chamber was cleaned so again that gave me knowledge.

And lastly, this is a huge learning process for me. I want to see exactly what effects changing certain parameters have on the outcome at the range. This rifle is kind of my sacrificial lamb so to speak. Once my competition rifles are ready to shoot I will be moving over to them and starting over. Hopefully being able to transfer a lot of lessons learned. I wont be quite so abusive to them albeit I will more than likely find where my upper end in pressure is and then find a load below that.

This rifle will soon become a bit of a safe queen. I really dont want to shoot out the barrel. This is a limited edition so I would like to keep original parts on it at least for now. However if I do decide to pull it out and shoot it at some point, Ill know what to load up for it.

This is not how OCW works. It's not designed to be splitting hairs between .1 grain increments. OCW nodes tend to be roughly .7gr apart, from what I recall when talking with Dan about it a year ago or so. Dan is a good friend of mine, and I shoot matches up there every 4-6 weeks. If you're seeing that big of a difference between a .1gr difference in charge weight, you're not on a node, or there's another problem somewhere. OCW is about getting the center of the groups to all fall in the same spot. Precision (group size) is then tuned with seating depth.

[doctnj]

Well I ran through the gun show and grabbed up all the h4350. There was 4 lbs. Should be glad there was any at all. Did pick up some imr3031 for my gas guns but again only two lbs. Then went by one of the biggest reloading supply places in town and they had neither. They did have primers. No h1000 anywhere. I could have walked away with all the imr4350 I could carry. Anyone ever use that?

[LongRange]

yes...i shot 2800 rounds through my first 260 barrel with IMR4350.

[doctnj]

Upslide, thank you very much for your input. I appreciate everything I can get. I initially ran a .5 ladder and identified two nodes below max load. Then I went searching for another one above max. Same thing, course ladder done and found a load that shot quite well. Weather it was a "node" or not is kind of semantics. I knew two things going into this test. It was a smoken fast load and seemed pretty accurate. So now to verify. I went with .1 for a few below and a few above. Seems like all the numbers held in there. It just so happen that the very last group on the edge was tightest. So is this a load that I will continue to shoot? Not if I don't get the pressure to back off.

It's been expressed that finding a "node" center insures that if a load error happens, i.e. +- .5 gr, that it's still going to be good. And more than likely, when the new rifles are employed, that is where I will end up. Maybe I should call this testing something else so it doesn't cause quite the stir. I don't see an issue with finding a load that is dead on, has good numbers, and loading it. Except, I won't have the safety net of a little powder wiggle room. I am pushing you for knowledge.

[doctnj]

Is Imr4350 less temp stable? I may switch down the road because it's everywhere!

[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.

http://i1075.photobucket.com/albums/w435/doctnj/6.5CM%20measured.jpg

[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.