Help me make sense of this-Ladder Test

[Smokin7s]

So I shot a ladder test today at 500 yards for my new 6.5/284

Lapua brass
Federal 210m
140 hybrid target
4831sc

I shot a ladder test today with a 7mph 2:00 wind

It shot really well but my higher charged shots are lower it’s almost like I shot it upside down compared to what I thought it should be not disappointed in the results just confused. Any insight?

 

[Gungnir388]

what distance did you shoot this at? If at 100yds your faster muzzle velocities will be low. They are rising up to the first Zero point on the rising arc of the ballistic trajectory.

 

[Hickswr]

what distance did you shoot this at? If at 100yds your faster muzzle velocities will be low. They are rising up to the first Zero point on the rising arc of the ballistic trajectory.

If he shot that group at 100 yards, he needs to go back to factory loads or take up golf.

 

[KnowNothing256]

what distance did you shoot this at? If at 100yds your faster muzzle velocities will be low. They are rising up to the first Zero point on the rising arc of the ballistic trajectory.

I don’t think so, if it’s zeroed at 100 yds it almost certainly only touches line-of-sight once.

 

[KnowNothing256]

Also, I’d load up 5-10 rounds of 53.0 and see if it shoots, that lil pack around that charge weight looks very promising

 

[rustyinbend]

IMHO ... a ladder test without velocity measurements is like kissing your sister. It looks good from a distance, but it really doesn't do anything useful for you. Seriously though ... do you have the ability to measure velocity with a LabRadar or some other chronograph? That's what a ladder test is really all about.

 

[nn8734]

Id shoot an OCW.

Ladder tests are a waste of time, IMO. Rarely do the “flat spots” repeat across multiple ladders with the same components and charge weights.

 

[Gungnir388]

I don’t think so, if it’s zeroed at 100 yds it almost certainly only touches line-of-sight once.

Thats freaking funny. Your scope sits roughly 2” above your bore. Your bullet is rising up to your zero point which is where the bullet crosses the line of sight of your scope on the rising branch of the trajectory, if that bullet would continue on unobstructed it will intersect with the scopes line of sight once again on the falling branch of the trajectory. My bad I called it arc in my first post. Why do you think the military zeros at 25 meters to get a 300 meter zero?
Here’s an illustration. since he is shooting 6.5/284 this could be happening to much further out based on his ballistics. Yes this is a bolt action rifle but ballistics are ballistics, they rise then fall on their trajectories.

 

[Smokin7s]

Sorry guys, 500 yard test.

 

[KnowNothing256]

Thats freaking funny. Your scope sits roughly 2” above your bore. Your bullet is rising up to your zero point which is where the bullet crosses the line of sight of your scope on the rising branch of the trajectory, if that bullet would continue on unobstructed it will intersect with the scopes line of sight once again on the falling branch of the trajectory. My bad I called it arc in my first post. Why do you think the military zeros at 25 meters to get a 300 meter zero?
Here’s an illustration. since he is shooting 6.5/284 this could be happening to much further out based on his ballistics. Yes this is a bolt action rifle but ballistics are ballistics, they rise then fall on their trajectories.
View attachment 7732856

Go on, plug it in to a calculator. Here, did it for you; 100-yd zero, 6.5mm 140gr Hybrid Target at 2900 fps, local environmentals. Never have to dial negative elevation because it only touches LOS at 100yds.

ETA: You have to zero somewhere around 85 yards with this load and conditions to see any negative elevation result in the 4DOF, and that’s only -0.01 mil, nothing you could actually dial. To get more than a half tenth negative, rounded to a full click, you gotta zero at about 72 yards, crosses again at 125 yards.

 

[Smokin7s]

This is getting off hand and I have velocities give me a bit I’ll post them

 

[KnowNothing256]

OP, barrel harmonics/whip is the theory I've heard to explain what you're seeing. If the barrel is at the top of its vibration when the bullet clears the muzzle, it can hit higher on target even if it's a slower round. The farther you get the less this is true; at long enough ranges no plausible amount of barrel whip will overcome a lower MV.

I don't think anyone's ever definitively linked some measurable amount of whip to some MV, because it's too small to see without some super fancy equipment and the gun is moving in all kinds of ways under recoil normally anyway, so good luck picking out thousandths or ten-thousandths of muzzle vibration.

There are a lot of theories out there about OCW/ladders/MV nodes, and you'll get as many opinions as there are a**holes on here. It does seem to be a persistent theme that MV nodes aren't particularly reproducible if you run the ladder multiple times, and it tends to just average out to a fairly linear relationship of "more powder = more speed." Most people don't collect enough data to see it because none of us wanna burn up barrel life, components, or time doing it, we just want the final load.

The barrel whip thing seems to be a theory that can lead someone to choose a certain MV over another, "tuning" the whip for a certain range target, but I haven't seen any hard evidence that verifies that explanation.

YMMV

 

[Shootin Stuff]

Thats freaking funny. Your scope sits roughly 2” above your bore. Your bullet is rising up to your zero point which is where the bullet crosses the line of sight of your scope on the rising branch of the trajectory, if that bullet would continue on unobstructed it will intersect with the scopes line of sight once again on the falling branch of the trajectory. My bad I called it arc in my first post. Why do you think the military zeros at 25 meters to get a 300 meter zero?
Here’s an illustration. since he is shooting 6.5/284 this could be happening to much further out based on his ballistics. Yes this is a bolt action rifle but ballistics are ballistics, they rise then fall on their trajectories.
View attachment 7732856

Umm, wot?

Bullets don't "rising up to your zero point".
They leave the muzzle inline with the bore, at which point gravity starts pulling them downward.

From a purely muzzle velocity standpoint (ignoring all other factors), the faster projectiles will impact higher on target than the slower ones.

OP, ignore this guy.

 

[nn8734]

So I shot a ladder test today at 500 yards for my new 6.5/284

Lapua brass
Federal 210m
140 hybrid target
4831sc

I shot a ladder test today with a 7mph 2:00 wind

It shot really well but my higher charged shots are lower it’s almost like I shot it upside down compared to what I thought it should be not disappointed in the results just confused. Any insight?

What were the charge weights for the two bullet holes not labeled?

Also, barrel harmonics likely explains what you are seeing but at 500m its hard to pin it on that alone as any subtle changes in poa (sympathetic rear bag squeezing, breathing etc) shifting the verticle up or down can also explain it

 

[Gungnir388]

@Smokin7s
agreed getting off hand. If you have your mv from the tested charge weights then simply compare the hold from your testing mv to that of the low hits. You will find your answer there.

 

[Smokin7s]

What were the charge weights for the two bullet holes not labeled?

Also, barrel harmonics likely explains what you are seeing but at 500m its hard to pin it on that alone as any subtle changes in poa (sympathetic rear bag squeezing, breathing etc) shifting the verticle up or down can also explain it

They were 53.3 and 53.5

 

[nn8734]

They were 53.3 and 53.5

I’d do a quick 3-shot OCW using 52.8, 53.1 and 53.4 and see if your groups’ center POI is the same relative to POA across all three and they each group tight. If so, MV is satisfactory and no over pressure is present, I’d load up 60-100 rounds of 53.1 and start collecting drop data on steel in 50m increments out to how far you plan on shooting it.

I’d be surprised if your load (assuming it does good at 100) doesn’t hold up at distance as long as the round is still supersonic and you execute correctly.

My .02.

 

[CK1.0]

Id shoot an OCW.

Ladder tests are a waste of time, IMO. Rarely do the “flat spots” repeat across multiple ladders with the same components and charge weights.

Ummm... don't tell anyone, but that OCW nonsense is a waste of time too.

Pick a speed, figure out how much powder it takes to get there, done.

 

[nn8734]

Ummm... don't tell anyone, but that OCW nonsense is a waste of time too.

Pick a speed, figure out how much powder it takes to get there, done.

Lol, ok….that method works fine if you know the cartridge well reloading-wise ( I do with 308, 223, 6.5 CMoor and know what charge weights will produce what speeds with a given set of components but if not, OCW helps determine your POI stability while tracking MVs along the way.

By time you figure out how much powder it takes to get to your target speed (unless you’re slow-playing) you will have shot an equivalent number of rounds for an OCW anyway.

Btw, wasn’t your user name something different just recently or am I getting you confused with someone else?

 

[CK1.0]

Lol, ok….that method works fine if you know the cartridge well reloading-wise ( I do with 308, 223, 6.5 CMoor and know what charge weights will produce what speeds with a given set of components but if not, OCW helps determine your POI stability while tracking MVs along the way.

By time you figure out how much powder it takes to get to your target speed (unless you’re slow-playing) you will have shot an equivalent number of rounds for an OCW anyway.

Btw, wasn’t your user name something different just recently or am I getting you confused with someone else?

All this Ladder/Node/OCW stuff is more religion than science. There are also people out there called "flat earthers" that still think ... well, you get the idea.

Seriously, you, me, and everyone else on the forum could burn up all of our/their components trying to prove me wrong and there still wouldn't be enough empirical data to amount to dick. It's a Rorschach test; people see what they want to see.

Harmonics; however, are real. If one is going to burn up components on load development, then seating-depth/bullet-jump is a more worthy campaign.

(...and yes, I changed my username from ceekay1 to CK1.0, same moron.)

 

[nn8734]

All this Ladder/Node/OCW stuff is more religion than science. There are also people out there called "flat earthers" that still think ... well, you get the idea.

Seriously, you, me, and everyone else on the forum could burn up all of our/their components trying to prove me wrong and there still wouldn't be enough empirical data to amount to dick. It's a Rorschach test; people see what they want to see.

Harmonics; however, are real. If one is going to burn up components on load development, then seating-depth/bullet-jump is a more worthy campaign.

(...and yes, I changed my username from ceekay1 to CK1.0, same moron.)

Sounds like fun, haha. Yes seating depth is definitely worth while though i will say you can apply the same logic to it with just a couple caveats:

1) most hybrid type bullets and tangent ogive bullets are not particular beyond ~.020” jump.

Example: 169 smk, 308: im jumping them .040” in one rifle and .192” in another (yep, .192 - that’s not a typo). They both shoot tight at 42.7g Varget and 43g of IMR4064. Perfect example of pick the charge based on the speed you want and seat to fit in the mag) but you need to know that otherwise you’re still working up to get there in your rifle.

2) this doesnt apply to secant / pure vld bullets. Seating depth is much more of a factor with those, at least what ive personally seem with them.

I am curious to see @Smokin7s mv data as im not real familiar with the 6.5-284 but am contemplating a magnum-class 6.5 build…

 

[CK1.0]

Here's the thing with powder: in theory, if we were to put the same exact weight charge in every case (while using brass and bullets that are as identical to each other as we can manage), then our muzzle velocity should be consistent, with low ES/SD's - no magic necessary.

Except, for some dumb reason, seems like practically nobody does that.

People go all-in on this OCW/Ladder-Test/node nonsense when what they probably really need is a better scale, or maybe a better way of dropping more consistent powder charges so they're exactly the same every single time.

If we're honest about it, putting too much emphasis on groups (shot by humans, not robots) and then making decisions based off of them is a terrible way to arrive at anything material. No one, not even the best in the world, can roll up to the range and shoot group, after group, after group, identically, same effort, same performance, every time... nope.

We can try to weigh shit the same every time though.

 

[Smokin7s]

Sounds like fun, haha. Yes seating depth is definitely worth while though i will say you can apply the same logic to it with just a couple caveats:

1) most hybrid type bullets and tangent ogive bullets are not particular beyond ~.020” jump.

Example: 169 smk, 308: im jumping them .040” in one rifle and .192” in another (yep, .192 - that’s not a typo). They both shoot tight at 42.7g Varget and 43g of IMR4064. Perfect example of pick the charge based on the speed you want and seat to fit in the mag) but you need to know that otherwise you’re still working up to get there in your rifle.

2) this doesnt apply to secant / pure vld bullets. Seating depth is much more of a factor with those, at least what ive personally seem with them.

I am curious to see @Smokin7s mv data as im not real familiar with the 6.5-284 but am contemplating a magnum-class 6.5 build…

Those are yesterday’s speeds off of a v3 never had any pressure. I had one round pressure in today’s testing at 52.5 with normal for the charge velocity which I thought was odd but it’s fresh lapua brass so I’m guessing maybe a neck tension issue? Anyway there were heavier charges after that one with no pressure at all. I’m guessing just a fluke deal.

 

[Smokin7s]

I think I’m going to put 53.0 in them and load some at 5thou higher and lower seating depth see which ones it likes better and roll with it.

 

[nn8734]

Those are yesterday’s speeds off of a v3 never had any pressure. I had one round pressure in today’s testing at 52.5 with normal for the charge velocity which I thought was odd but it’s fresh lapua brass so I’m guessing maybe a neck tension issue? Anyway there were heavier charges after that one with no pressure at all. I’m guessing just a fluke deal.

Yea, for a sample of one (one round per cw) that’s normal. Could be anything (maybe you breathed on it before loading it into the magazine haha).

It’s also why I don’t like comparative analysis on samples of one (you need minimum of 20 rounds, 30+ is ideal for statistical sampling purposes).

For now, All you need is ball park MV so you can develop a predictive algorithm for your rifle. Then validate based on real world impacts on target. Don’t sweat small deviations between predicted and actual; large differences should be investigated to determine the reasons for them.

ETA: bring your chrono when you do your drop validation so you can get a good sample size worth of MV data to refine your loads ballistics in your app of choice.

 

[supercorndogs]

All this Ladder/Node/OCW stuff is more religion than science. There are also people out there called "flat earthers" that still think ... well, you get the idea.

Seriously, you, me, and everyone else on the forum could burn up all of our/their components trying to prove me wrong and there still wouldn't be enough empirical data to amount to dick. It's a Rorschach test; people see what they want to see.

Harmonics; however, are real. If one is going to burn up components on load development, then seating-depth/bullet-jump is a more worthy campaign.

(...and yes, I changed my username from ceekay1 to CK1.0, same moron.)

No not even close. Please read up and quit spouting bullshit. When building this theory scientist and engineers were consulted, and mountains of data were collected. Maybe what ever half assed method you thought was OCW might fit your description.

http://www.ocwreloading.com

 

[spife7980]

No not even close. Please read up and quit spouting bullshit. When building this theory scientist and engineers were consulted, and mountains of data were collected. Maybe what ever half assed method you thought was OCW might fit your description.

http://www.ocwreloading.com

Agreed, people who say load development doesnt work just dont have very high standards.

@Smokin7s What made you focus only on that specific 52-53.5 interval of powder? Based on what I see there I would go with ~53 but I would have tested a 4 grain spread in .4 gr intervals looking for some wider patterns and pressure which is where ladder testing has its place vs this very narrow window.

 

[nn8734]

Here's the thing with powder: in theory, if we were to put the same exact weight charge in every case (while using brass and bullets that are as identical to each other as we can manage), then our muzzle velocity should be consistent, with low ES/SD's - no magic necessary.

Except, for some dumb reason, seems like practically nobody does that.

People go all-in on this OCW/Ladder-Test/node nonsense when what they probably really need is a better scale, or maybe a better way of dropping more consistent powder charges so they're exactly the same every single time.

If we're honest about it, putting too much emphasis on groups (shot by humans, not robots) and then making decisions based off of them is a terrible way to arrive at anything material. No one, not even the best in the world, can roll up to the range and shoot group, after group, after group, identically, same effort, same performance, every time... nope.

We can try to weigh shit the same every time though.

Who are you trying to convince and why?

 

[CK1.0]

Who are you trying to convince and why?

Hahaha I'm not. I know the true believers will never be dissuaded.

I was just throwing another way out there that works...

Or, maybe it doesn't work and there's just a bunch of us who are lucky?

I mean, a lot of people who are balls deep into the OCW thing and finding nodes and such are also the same people that told me my guns would never shoot for shit if I didn't break-in my barrel correctly and... doh, lucky again

 

[supercorndogs]

No they aren't. Quit making shit up. Basically, You came to the conclusion you can't shoot well enough to be able to do load development, or you don't want to put the time in. Some of us are not afflicted with that problem. You clearly have a very tenuous grasp on the subject matter of reloading in general. Cool yer ammo is "guud enuf".

 

[Smokin7s]

Agreed, people who say load development doesnt work just dont have very high standards.

@Smokin7s What made you focus only on that specific 52-53.5 interval of powder? Based on what I see there I would go with ~53 but I would have tested a 4 grain spread in .4 gr intervals looking for some wider patterns and pressure which is where ladder testing has its place vs this very narrow window.

I tested in .3 increments on my first one I went with that 52-53.7 on the second one because those are the speeds I was comfortable with the first test was 51-54 but I narrowed down to what I wanted to know more about.

 

[spife7980]

Gotcha, sounds good. Now Id shoot some groups in .1 increments and see what lays down best out there and see if its up to your goals.

 

[Seymour Fish]

So I shot a ladder test today at 500 yards for my new 6.5/284

Lapua brass
Federal 210m
140 hybrid target
4831sc

I shot a ladder test today with a 7mph 2:00 wind

It shot really well but my higher charged shots are lower it’s almost like I shot it upside down compared to what I thought it should be not disappointed in the results just confused. Any insight?

Interesting. Did you shoot with magnetispeed attached to bbl ? How many rounds on this new bbl ? Describe the System: bbl length/profile, stock/chassis, balance point, bipod vs front rest, etc.

 

[Smokin7s]

Interesting. Did you shoot with magnetispeed attached to bbl ? How many rounds on this new bbl ? Describe the System: bbl length/profile, stock/chassis, balance point, bipod vs front rest, etc.

40 rounds bipod 26 inch proof sendero carbon mcmillan bedded

 

[Seymour Fish]

40 rounds bipod 26 inch proof sendero carbon mcmillan bedded

Ladder does look like a case of negative compensation. I would shoot your tight node in 0.1 gr increments of 3-5 shots. Look for a totally flat waterline that is very wind sensitive. The next increment up should be $$$

 

[CK1.0]

40 rounds bipod 26 inch proof sendero carbon mcmillan bedded

If you’ve only got 40 rounds on the barrel, then you still need to shoot at least 60-110 more rounds before doing any of this crap or you’re just wasting your time (and to a certain degree, by starting this thread before having done that, ours too ).

It taking 100-150 rounds before a new barrel becomes stabilized and stops speeding up is a fact.

 

[supercorndogs]

So....... Load development doesn't matter, but you need 100-150 rounds before you can start. Spoken like someone who hasn't shot enough barrels to know, not all barrels speed up. I can't think of a cut rifled blank ever speeding up on me in fact. Or any reason I would want to burn up that much barrel before starting load development.

 

[CK1.0]

So....... Load development doesn't matter, but you need 100-150 rounds before you can start. Spoken like someone who hasn't shot enough barrels to know, not all barrels speed up. I can't think of a cut rifled blank ever speeding up on me in fact. Or any reason I would want to burn up that much barrel before starting load development.

I never said load development doesn’t matter, I just don’t do stupid shit that doesn’t make sense according to like science and shit . I’ve probably already forgotten more than you’ll ever know.

Like your OCW BS with this elusive “mountain of data” and “scientists and engineers consulted” that is nowhere to be found.

Ask someone who actually works with combustion about your OCW crap and they will flat out laugh in your face because it’s a joke.

“That’s the way we’ve always done it” isn’t load development, it’s stupidity.

You’re so pompous that you don’t even realize how blind you are… All barrels speed up a little due to the first projectiles providing sort of a “final polish”, simple and easy explanation, no magic.

(BTW/FWIW, I’ve burned out 4 barrels since 10/1 of last year… loaded and shot ~9000 rounds over the past year if you’re keeping score.)

 

[spife7980]

You’re so pompous that you don’t even realize how blind you are…

Pot, meet kettle