Avoid this pitfall with distance/target based ladder test

[Feniks Technologies]

The way I’ve heard people define positive compensation seems as illogical as thinking bullets shoot tighter as distance increases.

It’s definitely interesting.

Finding a load range that exits higher and lower in the vertical barrel vibration at the damn near perfect time so faster and slower rounds have a similar waterline.

Alex Wheeler is a proponent.

Combine that with relatively low round count load development to get there…..

It’s definitely easy to question the validity.

For what it’s worth, it’s a similar theory to OCW. Varying powder charges which have same POI. It’s essentially positive compensation @ 100yds.

I’m absolutely ok with either method being completely valid or completely false. But I haven’t seen long term data that suggests either is reliable. Granted, that’s a task in a half to test enough to truthfully validate.

 

[MarkyMark007]

tuning for the distance is covered in the bottom of the page:

Barrel Tuner Analysis -- FEA Dynamic Analysis of Esten's Rifle with/without a Tuner.

at that picture: http://www.varmintal.com/600yd-trajectory-chart.png

but I asked erik cortina, but they dont do it that way. so I think they dont believe in this.

but if positive compenzation exists, why everybody are chasing the smallest ES/SD for the long distance?

but if only small ES/SD will hold tight water line in long range, than positive compensation does not exist...

than our nodes are not signs of positive compensations, but more of a sign of small ES/SD and tight water line, which are all for...

 

[Feniks Technologies]

tuning for the distance is covered in the bottom of the page:

Barrel Tuner Analysis -- FEA Dynamic Analysis of Esten's Rifle with/without a Tuner.

at that picture: http://www.varmintal.com/600yd-trajectory-chart.png

but I asked erik cortina, but they dont do it that way. so I think they dont believe in this.

but if positive compenzation exists, why everybody are chasing the smallest ES/SD for the long distance?

but if only small ES/SD will hold tight water line in long range, than positive compensation does not exist...

than our nodes are not signs of positive compensations, but more of a sign of small ES/SD and tight water line, which are all for...

Because some very high level don’t chase SD.

Ironically, you posted recent world record that seats by feel on primers…..

But he also used a positive compensation ladder.


So, which one is it? Or are you like most and just screenshot the part you like?

 

[MarkyMark007]

But he also used a positive compensation ladder.


So, which one is it? Or are you like most and just screenshot the part you like?

I dont know, and we discuss.

but I lean to the idea, that there is no 'positive compensation' that it works only for one distance, that there will be bigger group ar 500y than in 1000y, because at 1000y is the best 'compensation'.

 

[esorensen]

Gentlemen, I LOVE the discussion; argument if you will. It is the essence of our affliction. We over think, load, shoot, dissect, gather data, and so forth…ad nauseaum. We are today so far from where we were as a community not even 20 years ago. I embrace all of these differing opinions and try and find what works best for me and my applications. Makes my work less; or perhaps more. Oh, and the entertainment value…I can’t even say how incredible it is to have so many differing opinions on a given subject. Forum…Roman. Allow an intelligent person to expound on their knowledge for the benefit of others; and allow other intelligent listeners to take in or take apart the subject and lend your argument validity or not. No harm, no foul. Just discuss. For the benefit of all. In another 20 years, we will all be shooting the same hole at any distance using the same techniques…yeah maybe not. Feelings and internet (along with much else) are not congruent. Cheers!

 

[2aBaC̶a̶]

The way I see it there are 3 accuracy cones working at any given time.

(1) the ammo
(2) the rifle
(3) the shooter

 

[smoothy8500]

The way I see it there are 3 accuracy cones working at any given time.

(1) the ammo
(2) the rifle
(3) the shooter

And #3 exerts the most influence overall.....

 

[Seymour Fish]

tuning for the distance is covered in the bottom of the page:

Barrel Tuner Analysis -- FEA Dynamic Analysis of Esten's Rifle with/without a Tuner.

at that picture: http://www.varmintal.com/600yd-trajectory-chart.png

but I asked erik cortina, but they dont do it that way. so I think they dont believe in this.

but if positive compenzation exists, why everybody are chasing the smallest ES/SD for the long distance?

but if only small ES/SD will hold tight water line in long range, than positive compensation does not exist...

than our nodes are not signs of positive compensations, but more of a sign of small ES/SD and tight water line, which are all for...

Funny thing about Cortina method : it’s simply a 3 shot per incremental powder charge Audette Ladder, seeking an area where vertical displacement from POA is the same across some increments. spreading the POA horizontally makes for easier reading at 100 yds, where a single POA in a system with relatively little positive compensation may obsecure exact placements of individual shots. Recent testing with 90 vlds in a 223 truck axle with varget as an example of the positive compensation pitfalls one may encounter : Varget ladder showed no node, simply put everything into a .4” group At 100. H4895 ladder demonstrated typical upward displacement of impacts until a node was found across 0.2 gr, measuring 0.15”.

 

[V-Ref]

Is Greg from Primal Rights posting for Feniks now?

 

[Feniks Technologies]

Is Greg from Primal Rights posting for Feniks now?

Nope. Feel free to correct anything you see that’s wrong.

Post up your long term data and we’ll compare it to ours and several others such as @Ledzep

Always up for learning something new.

 

[Feniks Technologies]

Funny thing about Cortina method : it’s simply a 3 shot per incremental powder charge Audette Ladder, seeking an area where vertical displacement from POA is the same across some increments. spreading the POA horizontally makes for easier reading at 100 yds, where a single POA in a system with relatively little positive compensation may obsecure exact placements of individual shots. Recent testing with 90 vlds in a 223 truck axle with varget as an example of the positive compensation pitfalls one may encounter : Varget ladder showed no node, simply put everything into a .4” group At 100. H4895 ladder demonstrated typical upward displacement of impacts until a node was found across 0.2 gr, measuring 0.15”.

I don’t believe he uses that technique anymore either, even though the thread is still on AS.

I took his class a few years ago and it was pretty much all chrono for powder charge testing (not even shooting a target) and seating depth after.

 

[MarkyMark007]

I took his class a few years ago and it was pretty much all chrono for powder charge testing (not even shooting a target) and seating depth after.

that's what he said to me also. first only chrono for smallest ES/SD and than seating depth for group, because seating depth wont ruin good ES/SD from powder charge.

 

[Seymour Fish]

that's what he said to me also. first only chrono for smallest ES/SD and than seating depth for group, because seating depth wont ruin good ES/SD from powder charge.

This entire thread is based on a highly Improbable outlier “pitfall”. That is not what Experience dictates, nor is it how the smart money bets.

 

[Feniks Technologies]

This entire thread is based on a highly Improbable outlier “pitfall”. That is not what Experience dictates, nor is it how the smart money bets.

It is however, what every actual proper data collection has proven to be the case.

Unfortunately, there are just about zero long term testing that shows you can somehow beat the velocity + BC math at distance.

The only *proof* comes from low round count or “so and so won and does it this way”.

We haven’t even begun to address the vertical dispersion at distance due to bullet to bullet BC variance. Which can obviously be helped via trimming and tipping. But yet again, unless you’re able to measure it, (most aren’t rubbing oehler screens or Doppler), you’re still just pawing in the dark.

For example, a 10 shot string with an ES of 12, and a BC variance of .010 can have a maximum vertical dispersion of 8” @ 1k yds.

So, when you shoot 1 or 3 shots and you aren’t measuring *both* velocity and BC, you literally have no idea if you next 1 or 3 shots in your ladder test are because of positive compensation or just a difference in BC and/or Velocity.

“Experience” doesn’t equal fact. Experience used to say the world was flat.

Here’s a brief sample of how possible the above scenario is:

 

[Feniks Technologies]

This entire thread is based on a highly Improbable outlier “pitfall”. That is not what Experience dictates, nor is it how the smart money bets.

Also something to remember, the “highly improbable” is exactly why people think there are velocity flat spots.

The exact same high and low velocity shots that create these flat spots are the same that can show positive compensation at distance.

 

[jakelly]

The front line of accuracy and understanding has never been driven by statistics. It has always been driven by shooters that believe perfection is possible, that the equipment should work perfectly, that they didn’t pull the shot.

Statistics completely misrepresent reality. How about an example? Statistically explain how Tac Ops can consistently produce rifles that shoot in the 0s with factory ammo, on an outdoor range, with no machine rest, across multiple shooters. Mike guarantees 1/4”. What would WEZ say about that? Not possible? WEZ operates off of flawed logic, it’s not remotely accurate and really good shooters already know it. Statistical significance is logically flawed, too. You guys are “proving” yourselves into a position where nothing is knowable. From my viewpoint you seem like you’re about two or three logical steps away from an accuracy existential crisis.

 

[Baron23]

The front line of accuracy and understanding has never been driven by statistics. It has always been driven by shooters that believe perfection is possible, that the equipment should work perfectly, that they didn’t pull the shot.

Statistics completely misrepresent reality. How about an example? Statistically explain how Tac Ops can consistently produce rifles that shoot in the 0s with factory ammo, on an outdoor range, with no machine rest, across multiple shooters. Mike guarantees 1/4”. What would WEZ say about that? Not possible? WEZ operates off of flawed logic, it’s not remotely accurate and really good shooters already know it. Statistical significance is logically flawed, too. You guys are “proving” yourselves into a position where nothing is knowable. From my viewpoint you seem like you’re about two or three logical steps away from an accuracy existential crisis.

Wow, I don't even know where to begin aside from I think that perhaps you flawed understanding of statistics and how they model real world phenomena.

IMO, it is statistics that do in fact show reality and the small data sets used to identify velocity flat sports that misrepresents same.

And I have zero idea TacOps rifle test fire targets are relevant. Maybe someone else can explain that to me.

I'm not nearly as experienced in reloading as many here..by a long shot. But I have collected a good amount of chrono data on various loads and factory ammo (50 or more points in the data sets), have seen ES/SD converge to much more stable figures after about 30 rounds in the set, how ES/SD are really misrepresented by smaller data sets, and I have plotted these data with the application made available by a member here and I'll be damned if I have seen anything that looks like a valid (as in repeatable) velocity flat spot with increased powder charge.

I will leave this debate for the better informed than I.

Cheers

 

[Feniks Technologies]

The front line of accuracy and understanding has never been driven by statistics. It has always been driven by shooters that believe perfection is possible, that the equipment should work perfectly, that they didn’t pull the shot.

Statistics completely misrepresent reality. How about an example? Statistically explain how Tac Ops can consistently produce rifles that shoot in the 0s with factory ammo, on an outdoor range, with no machine rest, across multiple shooters. Mike guarantees 1/4”. What would WEZ say about that? Not possible? WEZ operates off of flawed logic, it’s not remotely accurate and really good shooters already know it. Statistical significance is logically flawed, too. You guys are “proving” yourselves into a position where nothing is knowable. From my viewpoint you seem like you’re about two or three logical steps away from an accuracy existential crisis.

You’re talking 100yds. A WEZ absolutely doesn’t say this isn’t possible.

You also don’t know what Mike does and doesn’t do as far as how many barrels may or may not pass his QC spec. Case in point, top F and BR shooters constantly toss barrels in the corner that aren’t capable of their standard.

A Tac-Ops is subject to the exact same physics @ 1k yds as everything else.


Again, feel free to show any long term data that doesn’t line up when either doppler or BC screens are used.

It’s extremely easy to show. Just show one single statistically significant test that shows bullets hitting a target at distance where the math shows it shouldn’t impact. Just one single long term test to support your opinion.

 

[Feniks Technologies]

Wow, I don't even know where to begin aside from I think that perhaps you flawed understanding of statistics and how they model real world phenomena.

IMO, it is statistics that do in fact show reality and the small data sets used to identify velocity flat sports that misrepresents same.

And I have zero idea TacOps rifle test fire targets are relevant. Maybe someone else can explain that to me.

I'm not nearly as experienced in reloading as many here..by a long shot. But I have collected a good amount of chrono data on various loads and factory ammo (50 or more points in the data sets), have seen ES/SD converge to much more stable figures after about 30 rounds in the set, how ES/SD are really misrepresented by smaller data sets, and I have plotted these data with the application made available by a member here and I'll be damned if I have seen anything that looks like a valid (as in repeatable) velocity flat spot with increased powder charge.

I will leave this debate for the better informed than I.

Cheers

It’s not relevant. A 100yd test target isn’t the discussion at all here,

This is what happens with these data driven conversations. People without data keep making it a moving target. Either from misunderstandings or just grasping whatever helps their point.

 

[Govt Mule]

Also, many top F class and BR shooters don’t measure velocity.

Right or wrong, doesn’t matter. Many of them don’t use one.

Many more use velocity measuring devices than don't. I shoot with the top F- open shooters in the US, and all of us use them. You ask them, they can tell what velocity they're shooting. It is required on some of teams by the wind coaches so they make the proper calls for the shooter.

 

[Feniks Technologies]

Many more use velocity measuring devices than don't. I shoot with the top F- open shooters in the US, and all of us use them. You ask them, they can tell what velocity they're shooting. It is required on some of teams by the wind coaches so they make the proper calls for the shooter.

Oh I agree.

Just making sure I cover both sides of the coin.

 

[Seymour Fish]

Many more use velocity measuring devices than don't. I shoot with the top F- open shooters in the US, and all of us use them. You ask them, they can tell what velocity they're shooting. It is required on some of teams by the wind coaches so they make the proper calls for the shooter.

Knowing the MV of a proven good load , plugged into a ballistic calculator for try-dope is nearly universal. Shooting a match with chrono running may not conform to rules, depending, but would explain the occasional miss and serve to cull a piece of brass into the lake. A powder ladder on paper Don’t Lie. You find a node, or switch powder. Now yer getting somewhere , appropriately broadening your scope vs lost in the statistical fog. Shucks, best nodes have been described as Not occurring at velocity flat spots If Enough Statistical Power is applied, by folks on this thread , previously. Good single digit ES occurring on a node happens, mostly via proper construction with compatible components Tuned. Seymour

 

[Ridge_Walker]

Maybe because velocity is irrelevant to accuracy.

The Houston Warehouse Experiment consistently produced groups sizes smaller than the 'Gap of a Spark Plug' without measuring velocity. They were only concerned with accuracy at one distance as a measure of a rifle.

Making LR Dope without Velocity and BC by measuring or by calculation would take a lot of ammo and could be done. But why would you.

 

[supercorndogs]

 

[Seymour Fish]

I don’t believe he uses that technique anymore either, even though the thread is still on AS.

I took his class a few years ago and it was pretty much all chrono for powder charge testing (not even shooting a target) and seating depth after.

He used said technique when he was winning. Is that statistically significant ?

 

[Feniks Technologies]

He used said technique when he was winning. Is that statistically significant ?

Ah, the always popular straw man argument.

The smartest people on the planet at the time thought the world was flat. Were they correct?

Scott saterlee has won with his load development method when he was saying flat spots exists. Was he correct?


As always, this is what happens when someone asks for just a slight shred of proof.

This is incredibly easy to test. Show a long term test where bullets impact a target in a location which the velocity and BC don’t predict they will fall. If you can, AB will gladly let you shoot over their doppler and prove it.

So far, everyone has failed or is “too busy.”

 

[Feniks Technologies]

He used said technique when he was winning. Is that statistically significant ?

You also seem to be under the impression I’m saying ladder tests don’t work.

I’m neither saying they do or don’t work.



I’m pointing out a very often seen “false” positive. It’s an extremely simple concept. You can take your chrono and shoot at a distance where the velocity changes will push you up or down into the next charge weight and see it all day, every day.

Some have you have decided to turn this into a debate over ladder tests in general. Which is why I keep inquiring about testing. It’s very simple to test and relatively cheap. You can get a Labradar, and then a ~$2500 oehlar BC screen setup. And then show everyone how ladder tests fly in the face of velocity/BC predictions.

If that’s the debate you choose to have.

 

[Milo 2.5]

Ah, the always popular straw man argument.

The smartest people on the planet at the time thought the world was flat. Were they correct?

Scott saterlee has won with his load development method when he was saying flat spots exists. Was he correct?


As always, this is what happens when someone asks for just a slight shred of proof.

This is incredibly easy to test. Show a long term test where bullets impact a target in a location which the velocity and BC don’t predict they will fall. If you can, AB will gladly let you shoot over their doppler and prove it.

So far, everyone has failed or is “too busy.”

I'll tell you what, I am about forced out of any conversations that include record keeping, or data collection. Plus, in the grand scheme, doesn't really matter what I think or believe, and I wish more people felt this way.
On your last pic above, the slowest rd and the fasted rd had the highest BC. Which goes against any BC is higher with faster velocities which actually is a thing with a large enough sample. So, if we cannot control the BC's of massed produced bullets, our only weapon is a system of load dev that actually enables us to control vertical dispersion at distance. Operator choice it is.

The more I read from people who demand huge sample sizes, that documented data is proof, the more I am reminded of fauci telling me I need to follow science, which results in a system failure in my head.

 

[V-Ref]

Is this some type of tuning public service announcement, a discussion, or is there a question in here somewhere

 

[Milo 2.5]

Is this some type of tuning public service announcement, a discussion, or is there a question in here somewhere

LMFAO

 

[Feniks Technologies]

I'll tell you what, I am about forced out of any conversations that include record keeping, or data collection. Plus, in the grand scheme, doesn't really matter what I think or believe, and I wish more people felt this way.
On your last pic above, the slowest rd and the fasted rd had the highest BC. Which goes against any BC is higher with faster velocities which actually is a thing with a large enough sample. So, if we cannot control the BC's of massed produced bullets, our only weapon is a system of load dev that actually enables us to control vertical dispersion at distance. Operator choice it is.

The more I read from people who demand huge sample sizes, that documented data is proof, the more I am reminded of fauci telling me I need to follow science, which results in a system failure in my head.

If you want to equate medical science to statistics, that’s your choice. The logic is flawed IMO, but obviously your choice.

I also believe your opinion that we can’t control the BC that well isn’t complete. That’s why shooters in disciplines which require it sort/trim/point their bullets (well, some of them anyway). That’s how you uniform or at least attempt to uniform the BC.


This is why there are people who will drive a car everyday, but won’t get on a plane. Why people play state/scratch lottery tickets, and why casinos make money.

 

[V-Ref]

And the pearls of wisdom continue

 

[Milo 2.5]

If you want to equate medical science to statistics, that’s your choice. The logic is flawed IMO, but obviously your choice.

Agreed, the logic is flawed, my way of saying not all buy into statistics, esp in shooting, given past accomplishments w/o it.
Thing is, as one gathers data with a rifle, the data changes unless the conditions are linear, and one condition that is always changing, is the condition of the bore, as in fouling.
A 50 shot sample after fouling a clean barrel may not look anything like shots #122-172.

 

[Milo 2.5]

If you want to equate medical science to statistics, that’s your choice. The logic is flawed IMO, but obviously your choice.

I also believe your opinion that we can’t control the BC that well isn’t complete. That’s why shooters in disciplines which require it sort/trim/point their bullets (well, some of them anyway). That’s how you uniform or at least attempt to uniform the BC.


This is why there are people who will drive a car everyday, but won’t get on a plane. Why people play state/scratch lottery tickets, and why casinos make money.

I am not here to argue with you DT, just saying even replicating conditions to shoot a 50 shot sample size can be an undertaking.
Anyone who has used a Rifle Kuhl and not let the whole barrel cool to ambient temps before resuming should understand this. If the air coming out of the barrel is cool, but the outside of the barrel still warm, the first shot is amateur day.

 

[Tokay444]

The Houston Warehouse Experiment consistently produced groups sizes smaller than the 'Gap of a Spark Plug' without measuring velocity. They were only concerned with accuracy at one distance as a measure of a rifle.

Making LR Dope without Velocity and BC by measuring or by calculation would take a lot of ammo and could be done. But why would you.

Yes, but, how much what would wager those groups were shot with loads that would have exhibited very low ES? Just because they didn’t gather velocity data, doesn’t prove that they weren’t shooting loads with low spreads.

 

[jakelly]

A Tac-Ops is subject to the exact same physics @ 1k yds as everything else.


Again, feel free to show any long term data that doesn’t line up when either doppler or BC screens are used.

It’s extremely easy to show. Just show one single statistically significant test that shows bullets hitting a target at distance where the math shows it shouldn’t impact. Just one single long term test to support your opinion.

How could that possibly be shown? You keep talking about compensation as if it steers bullets, it doesn’t. The people that believe that witchery are going to be proven wrong. What tuning barrel harmonics does do, is help to ensure they leave at the same trajectory, mitigating the angular deflection of barrel harmonics from velocity variation and differing dwell time as it pertains to the projectile itself. Once the projectile leaves the barrel, physics is absolutely the rule, how could it not be? What we seek with tuning are groups that only have the velocity BC variation in the vertical component, not groups that exceed it.

Do the rifles sometimes out group the ES? Possibly maybe even probably, but that’s a function of the rest of the accuracy vectors and chance. I bet it won’t dependably repeat. But the phenomenon would probably never be noticed if the load wasn’t in tune with the barrel, or more appropriately rifle, harmonics.

 

[jakelly]

Yes, but, how much what would wager those groups were shot with loads that would have exhibited very low ES? Just because they didn’t gather velocity data, doesn’t prove that they weren’t shooting loads with low spreads.

Very low ES? I absolutely believe that, but why do you suppose that the barrel had to be 21 3/4”? Not 21-22” but MUST be 21 3/4”? My thought is that that’s where the rifle harmonics tuned.

 

[Tokay444]

Very low ES? I absolutely believe that, but why do you suppose that the barrel had to be 21 3/4”? Not 21-22” but MUST be 21 3/4”? My thought is that that’s where the rifle harmonics tuned.

Why does a guitar string need to be a certain length and tension to vibrate at a G?

 

[jakelly]

A lot of successful f-class shooters will say they use “positive compensation” to tune their loads.

But, when you ask them what reloading practices or testing methods they use, they basically just do the same load development they initially did but repeat it at the distance they will be shooting in competition. 600 yards or 1000 yards.

I haven’t met anyone yet that is willing to explain how to use reloading practices to tune for positive compensation which I would define as when the barrel is on the upswing for slower velocity shots such that the slower the velocity of the bullet the higher the angle of the barrel when the bullet leaves the barrel.

I would personally bet that definition of positive compensation doesn’t happen. I believe that’s as nonsensical as bullets steering back toward POA as distance increases. I don’t lump ladder tests to tune for harmonics in with that theory.

 

[2aBaC̶a̶]

How are you guys defining "positive compensation" ?

 

[jakelly]

Who?

 

[2aBaC̶a̶]

Anybody who is using the words.

 

[Ridge_Walker]

Yes, but, how much what would wager those groups were shot with loads that would have exhibited very low ES? Just because they didn’t gather velocity data, doesn’t prove that they weren’t shooting loads with low spreads.

Probably not large spreads at all. Though the powder charges, as long as they were bracketed within a couple of grains, were not important as I would have thought. Perhaps they located accuracy nodes by groups. My point wasn't that velocity ES doesn't matter. It was that the group is the proof. To do it time and time again to the that level of precision without anything but various rifles, perfecting handloads and knowing a few secrets is remarkable. One of a few things that surprised me was they came to believe that the magic barrel length was 21.75 inches for 308, 6mm and the 22s. You might want to read about it yourself.

 

[jakelly]

When I say “positive compensation” I’m referring to shooting a load that falls at the bottom or more usually top of a barrel oscillation. The barrel reaching the end of it’s oscillation creates a range where it is pointing in a very similar direction for a longer time. This way if your velocity varies the bullet is at least released on a similar trajectory arc. It provides some “positive compensation” for the fact that slower bullets leave the barrel at a different time and therefore angle than faster bullets.

 

[MarkyMark007]

How are you guys defining "positive compensation" ?

in post #52:

 

[Tokay444]

Probably not large spreads at all. Though the powder charges, as long as they were bracketed within a couple of grains, were not important as I would have thought. Perhaps they located accuracy nodes by groups. My point wasn't that velocity ES doesn't matter. It was that the group is the proof. To do it time and time again to the that level of precision without anything but various rifles, perfecting handloads and knowing a few secrets is remarkable. One of a few things that surprised me was they came to believe that the magic barrel length was 21.75 inches for 308, 6mm and the 22s. You might want to read about it yourself.

Dude, it was sub 300 yards. Relax.

 

[Milo 2.5]

Dude, it was sub 300 yards. Relax.

This made me laugh out loud. Every time I try to read about the indoor escapades, I ask what part of this equates to me, I don't have a warehouse, I hate shooting at 100 yards, so basically, I find it uninteresting,
Far from saying there is not some wisdom in it. When I go to the range for some load work and it is blowing 18mph, at least I never worry about how the warehouse guys would handle it, screw it, I don't care.

 

[Ridge_Walker]

The point of what I was bringing up is that what was done in the warehouse, was to eliminate all the external variables. What they did by repeatedly putting 5 rounds into 1 hole @ 100 is that they achieved and then proved a base line of zero dispersion. The 21.75" barrel length, especially in the 22s was the length that they believed eliminated barrel whip. The proof was the 'Groups' of 0.025" which gives you a starting place to measure for “positive compensation”. Past 100 (their primary distance) is where velocity variances would impact vertical dispersion. Obviously once enough groups were shot to have established/proved that math and the BC variation, you could change barrel length to reintroduce whip. At that point you could prove the effects, and possible benefits of “positive compensation” in tuning 'whip' for variations of velocity to minimize vertical dispersion.

Dude, it was sub 300 yards. Relax.

Always.

 

[Seymour Fish]

The point of what I was bringing up is that what was done in the warehouse, was to eliminate all the external variables. What they did by repeatedly putting 5 rounds into 1 hole @ 100 is that they achieved and then proved a base line of zero dispersion. The 21.75" barrel length, especially in the 22s was the length that they believed eliminated barrel whip. The proof was the 'Groups' of 0.025" which gives you a starting place to measure for “positive compensation”. Past 100 (their primary distance) is where velocity variances would impact vertical dispersion. Obviously once enough groups were shot to have established/proved that math and the BC variation, you could change barrel length to reintroduce whip. At that point you could prove the effects, and possible benefits of “positive compensation” in tuning 'whip' for variations of velocity to minimize vertical dispersion.


Always.

Walker, to further this line of reasoning, a repeatable example : take a 308, 30” medium Palma barrel which exhibits tunable whip at 100 yds on ladder test, with a solid node across 0.6 gr powder. ES averaging 12, yet 0.1 grain incremental 3-shot ladder spanning the node , at 1000 yds in light steady condition demonstrates groups much smaller than the ES alone would allow. In doing so, a truth is uncovered that the worshipers of statistics will never grasp: at a certain step, a perfect waterline will be found, except it is tremendously wind-sensitive and useless for competition. The next increment up will print the smallest round group, the next up will impact a couple inches higher and will be 50% larger, the next up will do the same, and eventually you go off the top of the meat of it. If you then load the best charge and shoot it at 100 for reference, the group will look like a snowman. Truck-axle barrels seldom show this pattern overtly , tending to clump a wide range of charges into a ragged hole at 100 on a ladder, thus emphasizing tight ES for long range accuracy, and some fussing with seating depth, neck tension, and perhaps a tuner to shape groups. Even so, occasionally a switch to a different powder may show a pressure rise differential that provokes discernible whip sufficient to allow node tuning. Which system is superior ? Easiest to keep in tune ? As it is understood how to construct a system to exhibit either phenomenon, it may come down to horses for courses. Seymour

 

[brianf]

i have a few questions about the compensation theory true or not makes no diff to me..

from what i understand the idea is to manipulate the load/seating depth so the bullet leaves the barrel at consistent specific time as the barrel is whipping/ moving randomly prior to the bullet leaving

hopefully that duration is long enough to allow for small variations in internal ballistics etc allowing the bullet to leave while the barrel is pointed in the same direction

that consistency is part of what guys call a "accuracy node" or a few other names (although i have seen the same name and different description more than a few times, which makes me insane lol)

unless im missing some descriptive posts positive compensation is usually spoked about vertical dispersion, above and below waterline etc?

i also notice that varmint al is often quoted as he is the only one online that has posted theoretical simulations of barrel whip, although he states that the motion studies he has done are in theory they are not simulated with firing a projectile, which changes everything

in his simulations the barrel is moving/whipping in all directions not just on the vertical axis


question, if compensation is a actual repeatable phenomenon and the barrel moves in all directions:

we should be able to adjust the load/ seating depth to create a linear group in any direction by timing the exit of the bullet

if we can time a barrel in the vertical plain what is what everyone calls positive compensation

we should be able to time the barrel in the horizontal plain or a "diagonal" plain

in theory we should be able to shoot the "waterline" POI left and right with limited or no vertical dispersion

or create a line from 7:30 to 1:30 etc

has anyone seen this or have pics that it happens?

if the barrel is moving randomly and we cannot make change the direcetion of the "line" we must be missing another variable because random movement is random.

or every barrel has its own random movement (which is likely) but its consistent to itself

which then furthers the idea that a specific rifle can create linear groups by tuning a load


thanks