Vertical Dispersion: Flat spots on the MV ladder test are meaningless

[David Milisock]

Absolutely no offense to anyone, but a single 3-5 shot group doesn't say anything. Show 60 shots.


Yes, @Tarmacshooter is a troll.

I like the concept of groups with a large number of shots. I use a similar method when cold bore sighting very thin barreled hunting rifle. Shoot a target with 3 rounds shoot 3 times each time over 15 to 20 range trips. Then I know how a load the regularly performs in a cold barrel .

 

[David Milisock]

This reminds me of the joke about the scientist and the engineer....the first is looking for "the perfect" answer and the second for "fit for puprose" answer....I am an engineer...always look for fit for purpose

I am not a competivie shooter, just a hunter. Old enough to have been loading before Satterlie, Audette or OBT theories were published. I used tuners before OBT and at times when the peole who sell them now, argued against them.

My first load developent was with a variation of OCW. I have used varations of ladder (combined MV and Elevation changes). I used QuickLoad and GRT. I have a load my friend loaded in his rifle that shoots 5 shots, .5" or less in his rifle, tried it in 3 others, same caliber, same brand, different barrel contour, different muzle brake, different country of manufacture and same results. Took two of these rifles to Africa and was very successful.

To say the "ladder is useless" while millions of people find it effective, is wrong.
You can say "I have another way" would be more appropriate....and let peole and time be the judge

What I am trying to say is, there are many was to get to your target, some are faster than others, some are better than others, but so mane ways have worked for decades now. Use what works for you. I use what works for me. Don't need to convert anyone...but always listening to see if something else is better, in times of scarce resources.

I guess I fit into the engineer mold. My son and I both have 30-06 and 8MM JS Mausers. I work loads for each caliber that work in both rifles. I have varmint rifles that are better than 1/2" shooters, I have a 6MM auto loader that's a 1/2" shooter and a 45 caliber magnum rifle that shoots 3 shot 100 yard 1 ragged holes, (too much of a pussy to shoot 5 shots). What I do works for me in terms of repeatability.

While my rifles have custom barrels they are not bench or other competition rifles, they are built for their specifictask. You can't carry 15 to 20 pound rifles into the field nor 30" barrels. While my developed loads are significant to repeatability it's rifleman skills in the field that makes the kill.

 

[Clancy]

In general terms yes. In short range especially if the wind isn’t howling you need a perfectly tuned rifle all day. To do that you have to chase the load.

My 3 Gun Agg at the IBS Nationals (last week) was a .2167. That’s fifteen 5 shot groups at 100yds and fifteen 5 shot groups at 200yds. That’s 150 record shots and it was good for 3rd place.

Hey congrats on that, by the way. That’s a killer agg.

 

[Dusty Stevens]

At Deep Creek we are working in the pits quite a bit , I would have to be part ninja to get ammunition loaded in time.

You shootin f-class or somethin?

 

[Dusty Stevens]

No I shoot OG BR, I’m too crippled to get up and down.

Yall need to hire a target crew. Too much work to do when shooting to mess with targets

 

[INTJ]

communication is part of the problem with this and many other threads.
i have shot once a year at deep creek since 2015. the guys at deep creek seldom do LOAD DEVELOPMENT for a 6mm 1000 yd rifle. they know most of the basic info, and just have to TUNE, sometime more than a little, to get a rifle to shoot. so IMHO, they tune, not LOAD DEVELPOPMENT.
i built a new 6 dasher and went to 15.5 from 15. i had to start from scratch, do a 20 shot/.2 step ladder, chart and plot and pick a couple of points to try with LOAD DEVELOPMENT then fine TUNE once i was close.
a real 20 shot ladder is a beginning tool of load development, not an end to load development.
a lot of people have missed the big picture

Mike,

Load development is the same thing as tuning. I have more than once shown up at Deep Creek with a new bullet/powder and done all of my load development there by shooting round robin tuning ladders. That's 4 or 5 different powder charges and 12-15 shots.

The only reason I might do initial testing at 300-400 yds is because I can't get to a 1000 yd range and I can at least find my powder nodes at short range.

 

[dgeesaman]

PV = nRT is like gravity. It's not a theory, it's a fact, and difficult to overcome.

It's a fact, for ideal gases behaving ideally.

But ideal gases do not exist. In fact, real gases behave sufficiently closely to an ideal gas in most situations. But Boyle's law does not accurately describe real gas behaviors in all situations. At 55,000psi in a rifle chamber, I suspect the ideal gas law is not adequate to explain all of the things we observe.

David

 

[DLT]

@Beiruty can't even begin tell ya the # of awesome 3 shot groups I've had that went to crap on shots 4, 5 and 6. Or that would NOT repeat.

AMEN BROTHER

 

[Tarmacshooter]

@Beiruty I believe your logic is pretty flawed. There are entirely to many variables at play from shot to shot. This is not an all things being equal scenario.

Variables from primer differences, brass differences, powder differences and bullet differences.

Very small variations in bullets will give different results.

The ladder method of tuning is the most popular form of tuning. It’s tried and trued. This gives you a window of accuracy across a lot of variables and wide margin of error for those variables.

Say what you want but there are FAR to many good shooters who use this method who have match wins.

This method can be used for tuning a hunting rifle, PRS rifle and Fclass rifle.

 

[6bra1k]

Original 1000 yards ladder test

You are being redirected...

i know i said i was done, but i had not looked at his so called "original 1000 yard ladder test"
so i went and read.... anyone with eyes will see THREE SHOT GROUPS..he even refers to them as GROUPS. so it aint original and it aint a ladder ......
now i am moving on

 

[Dave M.]

Load 10, 11 was selected as a candidate for best vertical dispersion
Load 17 was then selected as another candidate.

Load 17 won and was selected as the best load for this rifle/powder/bullet combo
View attachment 1364222

Personally, I find it incredible that you ignored load #8

 

[Dave M.]

From 25F to 140F, variance of 115F Delta MV is just 25fps
At 40F variance, the MV should not change more than 10fps or so.
View attachment 1364289

Your assumption of MV only changing 10fps over 40F is wrong. Pure and simple, it’s wrong. If you don’t believe me, shoot 10 rounds at 50F and the 10 more at 90F and if the difference is less than 10fps I’ll eat my shoe. Lol.

 

[Beiruty]

Personally, I find it incredible that you ignored load #8

I would have selected it. However, the test is not mine, and I have no control over it.

 

[Beiruty]

Your assumption of MV only changing 10fps over 40F is wrong. Pure and simple, it’s wrong. If you don’t believe me, shoot 10 rounds at 50F and the 10 more at 90F and if the difference is less than 10fps I’ll eat my shoe. Lol.

It could be true for the powder you use. Make your own tests and seen how much MV delta there is. a +-15 fps is maybe like +-1 0.25 MOA at 1000 yards

 

[Beiruty]

@Beiruty I believe your logic is pretty flawed. There are entirely to many variables at play from shot to shot. This is not an all things being equal scenario.

Variables from primer differences, brass differences, powder differences and bullet differences.

Very small variations in bullets will give different results.

The ladder method of tuning is the most popular form of tuning. It’s tried and trued. This gives you a window of accuracy across a lot of variables and wide margin of error for those variables.

Say what you want but there are FAR to many good shooters who use this method who have match wins.

This method can be used for tuning a hunting rifle, PRS rifle and Fclass rifle.

I provided my explanation for flat spot on the MV vs charge weight curve.
What is your explanation?

 

[Dave M.]

It could be true for the powder you use. Make your own tests and seen how much MV delta there is. a +-15 fps is maybe like +-1 0.25 MOA at 1000 yards

What you typed above makes zero sense and I refuse to participate in this frivolous conversation anymore. Your reply to my post in NO way is even remotely related to what I said
“+/-1 0.25 MOA”???????

 

[Beiruty]

What you typed above makes zero sense and I refuse to participate in this frivolous conversation anymore. Your reply to my post in NO way is even remotely related to what I said
“+/-1 0.25 MOA”???????

See here:
The Ballistic solution data is by Hornady 4DOF Solver:

225_ELD-M_3000fps_3030fps.xlsx

1drv.ms

 

[big5ifty]

I provided my explanation for flat spot on the MV vs charge weight curve.
What is your explanation?

The velocity flat spots are a convergence of one or more quality control errors.

There are many variables.

Taking only one variable for example : a +- 0.0015" variation in seating depth.

If the preceding round is seated short, and the following higher charge weight is seated long, the MV comes out the same or very similar.

If you get to the point where an increase in charge weight does not produce any increase in velocity, you have reached the point where there is more powder in the case than the barrel has time to burn.

 

[Tarmacshooter]

See here:
The Ballistic solution data is by Hornady 4DOF Solver:

225_ELD-M_3000fps_3030fps.xlsx

1drv.ms

@Beiruty ok at this point we all know your argument is flawed. No amount of data and experience to the contrary is going to change your mind.

Ballistic calculators use a static BC and Velocity to come up with a solution. This is only valid for that exact BC and speed. Unfortunately BC is different from bullet to bullet and lot to lot. May not be much but it’s enough to induce very minute error.

As we have shown velocity also changes with unknown variables. Again, the calculators are very good very close approximations.

Applied Ballistics runs around to PRS matches and ELR matches using their high dollar setup (including an advanced dopler radar) to give custom profiles (for their Kestrel Elites) for a shooter’s lot of bullets, powder, primers. It is only good for those items and that gun. Change 1 thing and the results may not be as good.

At the end of the day, you are wrong. WRONG. Your wiz bang hypothesis is flawed.

The fact that you referenced 4DOF is laughable btw. Anyone who relies on Hornady is suspect.

Good day.

 

[Tarmacshooter]

I provided my explanation for flat spot on the MV vs charge weight curve.
What is your explanation?

What are you asking? I don’t understand your question.