head spinning / info overload

[jippy1]

neophyte shooter,
got a few concepts I've been looking at that I am unsure how they relate (if at all) and when to use

I have the luxury of access to a 100, 200, 300 range with steel, and option to stake out targets to shoot dot drills, tall target tests, and targets for measuring m.o.a
I also have access to a 400, 500, 600, 700, 800, 900, & 1,000 with steel ipsc (full size, I guess) and also 1 m.o.a. steel

I have a chrono, and have strelock-Pro on my phone, as well as Hornady, and ballistic AE on my phone
I can get a range card with hold-overs for dialing, and generally make consistent hits out to 900

1) SO, WHATS WITH WEAPONIZED MATH?
got my head around it, but it seems like its just a way of roughing it in when you don't have MV, or something
or helping a student hit at a new distance, when the instructor has no info on that gum/ammo combo.
???when would I want or need to use weaponized math, if I know my MV, BC, environmentals???

2) SPEED DROP FACTOR
my grasp is that, first of all you have to have your own dope already
at each yardage, divide by 100, you then subtract your dope from that.
you then some how pick one of those numbers and decide what is your tolerable error limit (0.3, 0.2, 0.1)
you then subtract that error limit from the (almost speed drop factor) and dial UNDER that amount, THAT is then your SPEED DROP NUMBER
and this lets your range your target, and simply dial that number to target (I think)

this is from mountains, mullets, America, on YouTube
seems quicker, but is it as accurate as using actual dope?

3) weaponized math and speed drop factor don't really have anything to do with another???

4) still trying to get my head around truing
is it that I am truing the inputs (mv and bc) to put into the ballistic solver, so that it gives be BETTER DATA to dial (or holdover?)
it seems like folks tweak MV from 200 to 800, and bc from 800 on??
are those distance the same for everyone and every gun

 

[OREGUN]

1: a math trick to help get 10 people in a class on distant targets in hurry without having to chrono everyone. Works good. Provides an accurate swag for each 100 yard step based on the last.

2: sure, sounds good.
3: nope
4: making small adjustments to the quantities your computer uses to generate dope. The bullet doesn’t lie so if it takes 4.7 to hit, your calculator better say 4.7 or the MV or BC need to be corrected until it does. Velocity at 600 and BC at 800.

That’s the basics.

 

[6.5SH]

I'll go against the grain on #4.
If you have a good MV average from 30+ shots and a LabRadar, Magnetospeed or other lab grade chrono then that is a true number.
BC and velocity are coupled, why change the number that you know to be true? Any stated BC is not chiseled in stone.

I'll answer my own question there, these calculators all use various shortcuts to arrive at their predictions. If I had to make a relatively smaller % adjustment in MV to make a particular calculator line up then it is the right compromise. If it requires adjusting both ends to make it line up then so be it.

But... If your data is actually correct the math should line up in any decent program. What are you REALLY adjusting for then? Quite possibly something you the shooter are doing.

 

[OREGUN]

I'll go against the grain on #4.
If you have a good MV average from 30+ shots and a LabRadar, Magnetospeed or other lab grade chrono then that is a true number.
BC and velocity are coupled, why change the number that you know to be true? Any stated BC is not chiseled in stone.

I'll answer my own question there, these calculators all use various shortcuts to arrive at their predictions. If I had to make a relatively smaller % adjustment in MV to make a particular calculator line up then it is the right compromise. If it requires adjusting both ends to make it line up then so be it.

But... If your data is actually correct the math should line up in any decent program. What are you REALLY adjusting for then? Quite possibly something you the shooter are doing.

I don’t think you are “against the grain” at all.

There are a lot of interrelated factors and it’s more complicated than the standard dogma taught to new shooters as a way to get them started. For example: do you have enough samples over your chrono to have a good average? Is your zero good? Is your computer set up correctly? Is you ammo consistent? Is your shooting consistent? Is there an air density effect occurring that you aren’t aware of? Mirage? Is your vertical displacement at distance (the thing we are truing) a valid representation of your system’s capability (If you are a 2 MOA shooter at 100 and you hit anything smaller at distance, you statistically just lucked out and your actual impact location at distance will be over a larger area where that tiny group landed and thus where you just “trued” to)?

People use “my barrel is speeding up” the same way they use “I got effed by the wind”. It’s an excuse for their misses that easy to use and mostly incorrect.

Truing adjustments need to be reasonable, well considered, verified by time and reps, and typically small rather than large. But again, at a class of newbs, the basics allow a guy to get on target, without a chronograph, and have their impacts line up with their kestrel for the day/weekend.

 

[DocRDS]

I'm going to politely disagree with the above guys. (probably because I build statistical models for a living, so it warps my view)

Truing is about fitting a model. Your ballistic app, wherever it is, has a model inside. There are two things you can use to "tune" or "true" the model--aka make it match your real world results: MV, and BC. (technically there are few more lit your sight height, but you get the jist)

Remember all models are wrong: Some models are useful. You want your model to match your data!

The point being you want your ballisitcs app to match you real world collected dope. Now, I absolutely agree that you need good solid DOPE to match your model to. Trying to match a model to crappy data makes for a crappy model.

The rules of thumb for MV to 800, BC at 800+ are just that. Most differences below 800-900 yards involve playing with the MV for the ballistics app. Most differences at 800-900+ involve BC.

I will agree that many of the differences we see, may be due to things other than ballistics, but that goes back to DOPE. Record your aim point, Weather conditions (pro tip--Hornady match losses about 50fps when going from 85 to 30F), setup, etc.

You need GOOD data to true or tune your model.

However the group of ol timers who shoot F class weekly also told me. "Zero your rifle and get a good MV-- You'll be on at 1000 and can fine tune from there." so if you have to adjust that MV/BC too much something ain't right.

 

[OREGUN]

I'm going to politely disagree with the above guys. (probably because I build statistical models for a living, so it warps my view)

Truing is about fitting a model. Your ballistic app, wherever it is, has a model inside. There are two things you can use to "tune" or "true" the model--aka make it match your real world results: MV, and BC. (technically there are few more lit your sight height, but you get the jist)

Remember all models are wrong: Some models are useful. You want your model to match your data!

The point being you want your ballisitcs app to match you real world collected dope. Now, I absolutely agree that you need good solid DOPE to match your model to. Trying to match a model to crappy data makes for a crappy model.

The rules of thumb for MV to 800, BC at 800+ are just that. Most differences below 800-900 yards involve playing with the MV for the ballistics app. Most differences at 800-900+ involve BC.

I will agree that many of the differences we see, may be due to things other than ballistics, but that goes back to DOPE. Record your aim point, Weather conditions (pro tip--Hornady match losses about 50fps when going from 85 to 30F), setup, etc.

You need GOOD data to true or tune your model.

However the group of ol timers who shoot F class weekly also told me. "Zero your rifle and get a good MV-- You'll be on at 1000 and can fine tune from there." so if you have to adjust that MV/BC too much something ain't right.

How is this any kind of disagreement? We are all saying the same thing: good data in, good data out.

 

[DocRDS]

Only that your "measured" MV is never going to match the "input" MV or the "Published" BC or never going to match the "input" BC (except by lucky chance).
The goal is for the model to match your DOPE. Even in a perfectly measured MV on a perfect shooter won't exactly match the DOPE becasue the model itself is not perfect. The Values that go into the model are just "parameters" to adjust the model. I think its better if new(er) shooters understand--Its just a model, and they are just parameters to tune. Make the model match your DOPE. don't worry about a perfect match between chrony MV, input MV, published BC, and input BC.

 

[Baron23]

MV, and BC. (technically there are few more lit your sight height, but you get the jist)

Well, except he says he has Hornady on his phone...assuming 4DOF...which has drag curves like AB, right. So, again...and I'm far from expert at all...why would he mess with MV if he can distort the drag curve a bit to have a better fit to actual field performance?

 

[OREGUN]

Only that your "measured" MV is never going to match the "input" MV or the "Published" BC or never going to match the "input" BC (except by lucky chance).

Gotcha. Totally agree. I’m fairly certain that when Frank is doing this with noobs at his classes he literally has them put in box values for both and then they go from there on target. They never use a chronograph at all. I was just trying to point out that you need to have a lot of good information in the computer to give the model the best chance. If your site over bore height is wrong and your twist rate is wrong and your elevation is wrong and your temperature is wrong your models not gonna be anywhere near correct and it won’t have anything to do with muzzle velocity or BC.

if he can distort the drag curve

Isn’t that just another way of “adjusting” MV and BC in the modeling? The shape of the curve initially is mostly affected by velocity and then later on is mostly affected by the bullet‘s ability to resist slowing down?

 

[Baron23]

Isn’t that just another way of “adjusting” MV and BC in the modeling?

Eh, sort of. My understanding (which is probably utterly wrong! haha) is that calculators that use MV and bullet BC make a rough cut at a single drag coefficient for that bullet (based just on those two numbers. Calculators that use a radar derived drag curve for your bullet are deriving drag coefficients vs mach number as calculated from radar data taken as much as once every yard downrange and hence more accurate.

Now, in 4 DOF when you adjust Axial Form Factor, I'm not sure if it flattens the drag curve, moves it left/right, recalcuates the whole curve based a percentage diff from the standard curve for that bullet....and as said, I'm sure I'm not understanding this fully...or even at all.

Have a great day, my friend.

 

[Newbie2020]

@Enough Said invented weaponized math. We should get his 2c. @Lowlight teaches this every class. It works.

They said the Alaska guys don’t use software and this works at every altitude, humidity, and temperature.

 

[Enough Said]

Im at dinner. Respond tonight or tomorrow.
—-Taylor

 

[Mr. F]

A though on all of this that i don't think has been pointed out -

1% error on the chrono taking a speed sample of a particle going 3000fps is 30fps...

I don't know what the field conditions error on the labradar or the V3 i use are but i know i use em on a very wide range of conditions. I dont feed it a new battery each outing and it goes thru 10-20 warm cold cycles on my truck for weeks and sometimes months at a time.

the V3 Sometimes is .250" from the bore, sometimes .100"... eyeball stuff.

My point is the MV average over even a large sample can be off and while 30fps even 50fp is not enough to move the needle that much with a centerfire cartridge inside 600-700 yds, it will the further out you go. I think part of why you can run your MV and hit stuff at 4-500yds is the number being close enough to the unknown real value and your cone of probability stays inside most of your targets at shorter ranges.

I know of a lot of good shooters that don't even bother with a chrono when tuning solvers for matches because it really does not matter if the number is X or X+40fps as long as your watermarked out to distance on a calm day with good light, leveled against the fall of a plumb ect...ect...

A larger sample size will give you more resolution but that is independent of accuracy.

 

[Enough Said]

A chronograph is a great tool for developing a load that a barrel likes. However, they are inconsistent and not necessary to hit center plate on a target unless you are going to plug the numbers into a solver. It only measures the bullet's speed in one place. Bullets being different, even among same brand and type, means all bets are off once the bullet starts flying downrange, so we are done with the chrono once the load is developed.

Good fundamentals, good load and good equipment will produce consistent hits downrange regardless of a bullet's speed.

All objects are affected the same by gravity if launched from the same place and the downrange targets are on the same elevation plane or similar.

Weaponized Math is the drop factor (gravity) expressed in a multiplier, that will get you the next downrange hit under unknown conditions because of an unknown load / rifle. Use it then fine tune it then move to the next yard line. It was developed using known data of many rifles / loads under controlled fundamental conditions.

When targets are not on the same elevation plane, as is the case at Pala Range, Ca or Mifflin Co., PA, for instance, a Weaponized Math drop factor sheet can be developed for that particular range of targets and I have worksheets that are specific to Pala and Mifflin and they get us center hits on first round shots by students with unknown rifle/ammo combinations.

Weaponized Math WORKS and it does not lie. It does not need to be trued BECAUSE IT IS THE TRUE DATA.

It cannot resolve if inconsistent fundamentals are present, however so the shooter absolutely must do his/her part.

A solver is trued to weaponized math result, not the other way around.

Thanks for your questions, OP. Excellent questions.

Speed Drop Factor is a way of aligning your turret to your data to save time on the clock. It works as well, but must be trued to your weapon system.

---Taylor

 

[jippy1]

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