How far off the lands do you start?

[Castle Rock]

So you would auggest an appeal to authority and to ignore hard data dispelling the node dogma? What if world class shooters are chasing nodes that dont matter, and are unknowingly finding efficiency and accuracy through more important factors in their reloading process?

I started reloadong a year ago and went down the node route before learning that my groups were too small from the balisticians described above. My reloading is more efficient and less time consuming as a result. Listen to the Hornady series of podcasts with an open mind and get back to us. Lots of dogma in shooting sports... can only kill an elk with 300 magnum, etc., based off of poor data collection.

I start with seatin monos at 50-75 though off the lands, and bonded bullets at 0.25-0.50 assuming the magazine allows it. Might move back to SAMI length in 20-30 thou increments if accuracy isn't spot on.

So you started reloading a year ago and are talking about dogma with your wealth of experience

 

[jjohnsonElknewbie]

After reading some of these responses, I'm convinced my OCD is nothing compared to some folks. I've never tested seating depth beyond the sharpie method. I seat until no marks show, pressure test rounds all at the same seating depth, back off of pressure .5 grains, load 10 and see if they group. This has worked in 2 hunting rifles so far and I expect the 3rd I test this week will be the same.

First attachment is 10 shot group with 7-08 at 100 yards with Tikka action and barrel. Second is 10 shot group with 25-284 at 100 yards with Tikka action and McGowen barrel. I had a couple poor shots fall outside the bull on the last string and I'm blaming pretty severe mirage off my can.

 

[Harvey_NW]

Some world class shooters say nodes exist, you say they don't..........cool story bro.

Watch what happens when one of those world class shooters ups their sample sizes and starts applying statistical validity in this video. All of those world class shooters that actually test their theories end up with the same results, there is no difference and their extremely expensive and well built rifles just hammer. The ones that don't either won't test it, or are trying to sell you something.

But good luck on your reloading journey

 

[bnewt3]

Im becoming very confused.

If nodes dont exist, then any good bullet with any charge weight, any seating depth for a particular rifle shoots the exact same.

EDIT: any reasonable charge weight

If so then what are we doing?

Im also confused how a method that is clearly working can be so easily dismissed.

FYI, watching @Harvey_NW video now.

 

[satchamo]

I’m gonna sound contrary but I don’t think you can accurately measure 0.02 off the lands. At best you’re guessing using an oal tool or the jam method. For me I’m just making sure I’m back off of what id consider close to jam using a Hornady tool and even then I feel like I’m guessing. But if it chambers fine and fits my mag I usually call it good.

I’ve shot way too many vmaxs 2 miles off the lands accurately to think it matters…. But I do give it a college try.

 

[wind gypsy]

Im becoming very confused.

If nodes dont exist, then any good bullet with any charge weight, any seating depth for a particular rifle shoots the exact same.

EDIT: any reasonable charge weight

If so then what are we doing?

Im also confused how a method that is clearly working can be so easily dismissed.

FYI, watching @Harvey_NW video now.

I wouldn't argue with a dude who consistently is at the top of the heap in 1000 yd benchrest about nodes. I do know that with my equipment and abilities, all the ladder, OCW, "node" finding tricks are typically a waste of time and money. Either it shoots well enough to not be a contributing factors to me hitting/missing or it doesn't. I don't waste time trying to make a barrel, bullet, powder combo shoot that clearly doesn't want to anymore.

 

[bnewt3]

Finished the video.

First, I completely understand the importance of sample size. 3 shots, 5 shots, even 10 shots is not enough to get the full picture.

I think the conclusion(from this test) is not that seating depth doesnt matter, only that we dont know definitively if it does much less how much it matters.

I wish he went through all of the variables he controlled, such as barrel temp or at least time between shots OR tracking barrel temp, seating depth gaps, how long since last cleaning, etc.

I also wish he used more loads. Picking 3 loads based only on 3-shot groups when we know 3-shot groups are statistically irrelevant seems rather arbitrary because the point was to test seating depths, not prove 3-shot groups are irrelevant.

 

[bnewt3]

I don't waste time trying to make a barrel, bullet, powder combo shoot that clearly doesn't want to anymore.

Now that makes sense

 

[Harvey_NW]

Im becoming very confused.

If nodes dont exist, then any good bullet with any charge weight, any seating depth for a particular rifle shoots the exact same.

EDIT: any reasonable charge weight

If so then what are we doing?

Im also confused how a method that is clearly working can be so easily dismissed.

FYI, watching @Harvey_NW video now.

It's confusing because it's contrary to popular belief, the traditional generational dogma that's been passed down just doesn't hold water when tested at a scientific level. I shouldn't speak in absolutes because there could be a case for an old chamber design with sloppy tolerances and a specific bullet that maybe seating depth or jamming the lands does make a difference in precision/dispersion, I've just never seen it and ballisticians can't seem to replicate it.

For the most part the combination either shoots well, or it doesn't. They do say that in some cases dropping the powder charge and shooting a more mild load can measurably reduce dispersion, if it's worth the cost in velocity for your case.

In order to distinguish a certain seating depth or powder charge (nodes) exist, you'd essentially have to shoot to the point of group stability, or a true cone of fire. That would take hundreds of rounds testing each variable, and you'd likely smoke the barrel before you ever found the magical load. It's much easier to just use known quality components, slap some shit together, load .020"-.050" off the lands as best as you can measure (I prefer to use the cleaning rod clamps and measure from the bolt face to the tip of a bullet lightly finger pressed against the lands), do a pressure test, and shoot a fairly valid sample. If it doesn't shoot well, swap powder or bullet, rinse, repeat, until it does.

 

[Okie_Poke]

Im becoming very confused.

If nodes dont exist, then any good bullet with any charge weight, any seating depth for a particular rifle shoots the exact same.

If so then what are we doing?

Im also confused how a method that is clearly working can be so easily dismissed.

What are we doing, indeed. Query whether reloading is actually "worth it," but that's a different topic. I'm presuming a good faith desire to understand an opposing view point, and so I will try to help with that.

First, here are links to the Hornady podcasts mentioned a couple of times by others: Your groups are too small and Your groups are still too small. There are some important caveats to their claims that come through better in the second one: specifically, their testing is with Hornady bullets in Hornady-designed chambers like 6 ARC and 6.5 Creedmoor. (One might hypothesize, for example, that a VLD in a SAAMI-spec 300 Win Mag might be more sensitive to changes in seating depth than is a 6.5 Creedmoor with an ELDM, and I don't think Miles or Jayden would claim their testing rules that out). I don't treat the Hornady's information as gospel, but it is data-driven, thought provoking, and largely consistent with my own anecdotal experience chasing "nodes" and "best" loads that don't repeat on different days.

The big take-aways from those podcasts (going from memory here, so excuse me if I'm imprecise or miss something):

• You need to shoot 20 shots of a particular load before it begins to be statistically significant. More is better, though there is a point of diminishing returns. 10 shots starts to tell you something but still has significant variation you need to acknolwedge and so 20 is better. Anything less than 10 is a waste of time.
• Small changes in powder charge do not translate to substantial, verifiable changes in precision when you shoot statistically valid samples. In fact, if anything, lower powder charges tend to be more precise than higher powder charges.
• Small (and not so small) changes in seating depth do not translate to substantial, verifiable changes in precision when you shoot statically valid samples. (Again, note caveat on bullet and cartridge types here).
• Common load development methods like OCW, Satterlee, etc. do not identify loads/nodes that are consistently better than other combinations of the same bullet-powder-primer-case. Instead, what you are seeing when you shoot "small sample size" groups is random variation that, while the groups appear different, is "within the noise" or true cone of fire and thus statistically not different.

So why do all of those load development techniques "work" to identify accurate loads world class shooters win matches with? The Hornady guys would respond because that so long as you're using using quality components and good reloading processes, about any method will work to identify a good load. The 1-shot, 3-shot, or 5-shot methods are giving you a "confirmation spiral" where you think you're picking "the best" load but what you're really doing is picking a good load that's statistically the same as the load next to it. And world class shooters are world class shooters.

So does this mean that all load development is a complete wast of time and you're just as well off picking a random combination? Not quite. But, in point of fact, you can pick random recipes of quality components and do quite well with them.

I think everyone would agree that individual barrels often exhibit a preference for certain bullets over others. This has certainly been my experience. So, picking a "good bullet" doesn't necessarily ensure your barrel will like that bullet as well as it likes another "good bullet." Also, I have seen barrels that show a preference (or distaste) for particular powders. I had a 30-06 that hated IMR 4451, for example, while another 30-06 and a 6.5 Creedmoor liked that powder just fine. One of my Grendel ARs (but not the other) strongly prefers TAC over most other powders (read all others I've tested) with 120/123 class bullets. And Bryan Litz demonstrated in one of his books that changing from one brand of match-grade primer to another in a particular rifle/load reduced velocity variation (ES/SD) measurably, although precision measured at 100 yards remained the same. I, on the other hand, have never seen primer selection make a difference (although I admittedly don't test it very often).

So coming back to seating depth: does it matter? To paraphrase Bryan Litz again, "in what cirumstances does it matter, and do those circumstances apply to you?" I can personally get sufficient accuracy for my hunting and limited match uses by selecting bullet-powder combinations with an almost randomly selected jump (I described my process in an earlier post ) that I do not feel the need to do seating depth testing/tuning. It takes a lot of components to prove that a particular seating depth is better than any other. It's just not worth it to me. Either that bullet-powder combination shoots in that barrel, or it doesn't. If the load is finicky about seating depth to stay "in tune," I don't want to deal with it in the field.

For the Benchrest and F-Class guys? Hey, if you want to shoot in their disciplines, go listen to their advice. And get out your checkbook.

 

[jjohnsonElknewbie]

For the most part the combination either shoots well, or it doesn't. They do say that in some cases dropping the powder charge and shooting a more mild load can measurably reduce dispersion, if it's worth the cost in velocity for your case.

7-08 load dev left to right:

1- 162 ELDX over 47.2 gr of SB 6.5 (IIRC ejector swipes and slight bolt lift)
2- 162 ELDX over 46.7 gr of SB 6.5
3- 162 ELDX over 46.5 gr of SB 6.5

This is an 18" barrel so MV was taking a hit regardless. I don't recall what it measured for the first 2, but the 46.5 load avg is 2628 fps.

 

[TaperPin]

Im becoming very confused.

If nodes dont exist, then any good bullet with any charge weight, any seating depth for a particular rifle shoots the exact same.

EDIT: any reasonable charge weight

If so then what are we doing?

Im also confused how a method that is clearly working can be so easily dismissed.

FYI, watching @Harvey_NW video now.

Anything worth while will be repeatable, if the shooter understands why it shoots good or not. I tend to want to emulate the techniques of shooters that rather consistently produce good results, rather those who don’t believe the secret sauce even exists. Prior to the internet you often had to physically rub elbows with good shooters to see what works, but now anyone can sound as knowledgeable as those who actually are.

Mis-application of statistics is also rampant and folks are quick to jump on bandwagons based not on shooting results, but theories and computer models. With experiences from a single rifle folks are quick to declare universal truths. On the flip side, good shooters test things, but they don’t test every possible combination or the barrel would be burned out in the process.

One thing that is very hard to quantify is shooter experience and judgement, which drives mathematicians/statisticians nuts because they put too much emphasis on hard numbers. Time and time again someone will beat the tar out of a rifle’s statistics to find the best load with many hundreds or even thousands of rounds, when none of the groups should have been considered since they were so universally bad. With no statistics and simply a better barrel, it easily wins on target with almost no effort. A barrel is a consumable just like powder, bullets or brass, but too often is treated like a family treasure that can’t be touched or factored in to the equation - get rid of poor shooting barrels early on. The shooter’s time is also not infinite, or free, and should be part of the equation, but that doesn’t fit a formula either. Spend time on what matters most. When Michelangelo was painting the Sistine Chapel, he still had a contracted price, a time budget and had to stay focused on the things that mattered most.

It’s the best of times since never before have so many top shooters shared their accuracy secrets, and it’s worst of times if someone struggles to sort out good information from fluff.

 

[bnewt3]

It sounds like someone needs to actually test this stuff on a scale large enough to mean something, multiple cartridges, multiple manufacturers, factory guns, comp guns, cheap guns, expensive guns.

I am now taking donations to assemble the necessary volume of components to accomplish this.

 

[Okie_Poke]

It sounds like someone needs to actually test this stuff on a scale large enough to mean something, multiple cartridges, multiple manufacturers, factory guns, comp guns, cheap guns, expensive guns.

I am now taking donations to assemble the necessary volume of components to accomplish this.

People do test this stuff. https://thescienceofaccuracy.com/product-category/books-media/

 

[jjohnsonElknewbie]

7-08 load dev left to right:

1- 162 ELDX over 47.2 gr of SB 6.5 (IIRC ejector swipes and slight bolt lift)
2- 162 ELDX over 46.7 gr of SB 6.5
3- 162 ELDX over 46.5 gr of SB 6.5

This is an 18" barrel so MV was taking a hit regardless. I don't recall what it measured for the first 2, but the 46.5 load avg is 2628 fps.

Here are a couple other loads developed following the same process from the same 18" Tikka. Not gonna win a 1,000 yard match, but plenty good for hunting.

120 NBT over 44 grains of Varget (10 shots)
150 Federal Fusion over 48.5 grains of of SB 6.5 (20 shots IIRC)

I should've metioned it already, but this thread influenced my simplifed approach heavily.

https://rokslide.com/forums/threads/painless-load-development-mine.238400/

 

[TaperPin]

I really like Keith’s Winning in the Wind channel. Even the one where seating depth is challenged, he picked the best load before testing for that episode. I see it as evidence seating depth did matter, but the first group that fell apart wasn’t all that good to begin with, it only looked good originally because of how it was measured. Early on he foreshadows this by reminding the viewer that mean radius is different between measuring from absolute center of target or center of group. Measuring the right thing was more important than measuring the wrong thing very precisely.

It’s too bad the video of getting a new 308 barrel on his Remington receiver is no longer up. The quick load development episode for that rifle is still there. Together those two segments summarize a solid way to a fantastic shooting hunting rifle.

 

[bnewt3]

So you would auggest an appeal to authority and to ignore hard data dispelling the node dogma? What if world class shooters are chasing nodes that dont matter, and are unknowingly finding efficiency and accuracy through more important factors in their reloading process?

If by authority you mean someone(possibly others as well) that has proven their methods deliver? Im not going to throw that out, even if it is contradicted by data. Just like im not going to throw out my own personal results even if they contradict someone like EC.

As to the second question, anyone worth anything knows you change 1 variable at a time. We all have to make assumptions every day. Im going to assume a proven winner didnt accidentally find right combinations.

 

[wind gypsy]

Something to consider - Finding a 284 Win load to shoot 180 hybrids or a dasher load to shoot 105 hybrids very well (by rokslide standards) should not be a challenge.

 

[TaperPin]

As another data point, among many, is this comparison of 3 shot ladder tests to find nodes in a 308 hunting rifle backed up with larger groups that also confirm the same best and worst nodes. One set of tests was 800 rounds ago and it’s duplicated now for comparison. He does a good job of summarizing EC and what the Hornady boys have said, with what is seen in his rifle.

His takeaway is it made about 1/4 MOA difference, which may or may not be worth the time and money to shoot it for someone else.

 

[Okie_Poke]

As another data point, among many, is this comparison of 3 shot ladder tests to find nodes in a 308 hunting rifle backed up with larger groups that also confirm the same best and worst nodes. One set of tests was 800 rounds ago and it’s duplicated now for comparison. He does a good job of summarizing EC and what the Hornady boys have said, with what is seen in his rifle.

His takeaway is it made about 1/4 MOA difference, which may or may not be worth the time and money to shoot it for someone else.

That video is well done. For those not watching the video: he selected a seating depth using Cortina's method and then loaded 25 of those. He then picked the "worst" seating depth identified by Cortina's method and shot 25 of those 5, 5-shot groups of each he compiled into a composite group of 25 for each load. Very similar to what I challenged the OP to do seveal posts back. The "good node" group measured 0.861" with a mean radius of 0.287" while the "bad node" measured 1.129" with a mean radius of .332." Good shooting.

If I had gone to that trouble, I would definitely pick the seating depth that shot smaller in the test. Confidence is worth having. But . . . it's worth remembering that one should expect about 20% variability in size of even 25-shot groups. Is one group actually better than the other? Maybe? Probably a little? (I'm sure there's a statistical test that can actually asnwer that question). Is it worth your trouble? If I put 25 shots in 1.129" I'm rolling with it.