Any Tips for a New Loadbase User?

[Broz]

Now, if you've developed and saved your sight in Tract in this manner - THEN - when you go out to shoot at 1000 yards under your stated environmental conditions of:
station = 25.3
temp=67
hum=30
altitude=0

You would recall that saved Tract, enter these field conditions in the 'Environment Conditions - Field' value boxes, then make sure the 'Field Conditions is ON' box is checked, open the Results tab, and the Path and Click values should provide the correct dope for 1000 yd hits under your specified field environment atmosphere conditions. To get even more refined data, utilize the Spin Drift feature and the Coriolis feature at 1000 yds.

Making any sense?

Ok I am gettin it. Stick with me boys there my be hope!!

Phorwath, on your above quote it all matches up now to what should have been used for the 1000 yard group I posted, with the conditions I recorded at the time the group was shot. As you can see it was .25 moa high and I used 20.5 moa. Load base is now telling me 20.2moa... spot on!


Here is another question though. Why after recalling the track, and entering the current "field conditions" would you not just go to the " shoot" page and enter the range to get your dial ups? Instaed of going to the Results tab and moa path?

Jeff

 

[Pdvdh]

Here is another question though. Why after recalling the track, and entering the current "field conditions" would you not just go to the 'Shoot' tab and enter the range to get your dial ups? Instead of going to the Results tab and moa path?

Jeff

Jeff,
With the LB Mobile that's exactly what I do. Don't worry that I stated go to Results tab & moa path. I was refering to the Desktop version. With the Mobile version, what you proposed is the best way to get your dope - slicker than snot. You should get the identical dope with either Desktop or Mobile.

You're gonna fall in love with LB3! gun) gun)

 

[Pdvdh]

Here's a link to a Thread I started that describes in some detail the accuracy of the predicted 985 yard velocities I obtain with the Berger/Brian Litz G7 BCs combined with Gus's LoadBase 3.0 software - with the LoadBase DC value set at the factory default value of 0.5

http://www.longrangehunting.com/forums/f19/loadbase-3-0-mobile-w-g7-bc-test-results-46812/

Broz,
I'll trade you my chronographs for your .338 Lapua rifle that shot that 3-shot 1 1/4" group at 1000 yds! You either got exceptionally lucky, that rifle's a tack driver, you're a tack driver - or most likely a blend of predominantly the last two, and a little of the first (luck).

 

[Broz]

Here's a link to a Thread I started that describes in some detail the accuracy of the predicted 985 yard velocities I obtain with the Berger/Brian Litz G7 BCs combined with Gus's LoadBase 3.0 software - with the LoadBase DC value set at the factory default value of 0.5

http://www.longrangehunting.com/forums/f19/loadbase-3-0-mobile-w-g7-bc-test-results-46812/

Broz,
I'll trade you my chronographs for your .338 Lapua rifle that shot that 3-shot 1 1/4" group at 1000 yds! You either got exceptionally lucky, that rifle's a tack driver, you're a tack driver - or most likely a blend of predominantly the last two, and a little of the first (luck).

Phorwath, I read that thread, that was great work you did. But I must concur with what a few others said, I cant believe you shot at your chrony at 985 yards. I would never do that with my chrono.... My Swaro RF yes...

As for that group, we all know there was luck in volved. But on the other hand that group (which is 2 1/4" by the way) is the second group that rifle shot under 3" @ 1000 since I putthe 8~32 nxs on her. But you know how it is, if you shoot enough you wll get a smokin group now and then. That said the rifle with good conditions shoots consistantly .5 to .7 moa at 1000.

Thanks!

Jeff gun)gun)

 

[bigngreen]

The manual references sight in conditions as the enviro conditions that are present at sight in and field conditions are different from sight in conditions. You only use the standard enviro only if altitude is the only know parameter the standard conditions are always reference with only knowing the altitude.
There is a table for correcting the BC to ICAO form Std Metro but that is it.

The longest range corrections I have done have been closer to the ICOA standard but far enough of that it should have been at least a few MOA of if I was not using the correct data, a 1/10 of a MOA at over 2200yrds is fairly close.

I tweeked the sight hight to 2.1 and the sight in hight to .5 and no mater how I do it I get 20.2 MOA. Both ways.

This is really bugging me, I thought I was getting the hang of it.

 

[bigngreen]

Información enviada desde página de contacto de PatagoniaBallistics [FONT=&quot]This is what I got from PB. I cut out all the email address stuff and posted just the content.
[/FONT]




[FONT=&quot] Dear Mr. Mantha,



You are 100% right in your concepts. There is a misunderstanding somewhere regarding this. However the User's Manual has a complete chapter to explain that in enough detail.



Thanks!



PB


It came up on Longrangehunting.com that I should use ICAO standard conditions as my sight in environmental conditions. I have been under the impression that I want to input my current environmental conditions that are present at the range during sight in. Then use the Field conditions for shooting at another weather or altitude condition. Could you clear it up for me as to what data to use for sight in data in the environmentals. Thanks Rhian Mantha
[/FONT]

 

[Autorotate]

Broz,

The upper "sight in" conditions must always be ICAO Standard Conditions for Berger bullets, because their BCs are referenced to ICAO conditions, which are:
29.92 in/Hg
59F
0% RH

A bullet's BC rating only has any meaning to us if we know the associated atmosphere density (environmental conditions) that the bullet's BC is referenced to. Look in the LoadBase 3.0 Desktop edition User's Manual. Mine is Code version 3.0.0.3, on page 41. There is a section titled Ballistic Coefficient reference. It is in the portion of the User's Manual titled 7 - Modules -> Ballistics; the third page in under Ballistic Coefficient reference. There will be found a table identifying the various bullet manufacturer's BC reference for their published BCs. Berger, Nosler, Lapua, and GI APG use ICAO Standard Conditions as their reference environmental conditions. On the other hand Barnes, Hornady, and Sierra use "Standard Metro" environmental conditions as the reference for their advertised BCs.

So your Environment Conditions - Sight In values need to be changed to ICAO Standard Conditions for the Berger 300 grain Hybrid G7 BC. If you enter any other Environment Sight In conditions other than ICAO Standard Conditions for the Berger B7 BC, then you will have entered error into the LoadBase 'engine', because the BC you entered will have been incorrect - to the extent that the values entered for environmental conditions is different from ICAO standard 92.92 in/Hg, 59F, and 0%RH. LoadBase software assumes that the BC value is referenced to the ICAO Standard Atmosphere, so ICAO Standard Atmosphere environmental conditions should automatically appear as the default in the first Environment Conditions Sight In box for environmental conditions.

I'd like to get clarification from Patagonia on this point. Is this conclusion based on reference from Patagonia?

The reason I ask is because on page 42 of my user manual for version 3.0.0.4 states:

"The upper area corresponds to the atmospheric conditions that were present during the Sight-In procedure.

The lower area cooresponds to the actual, Field conditions as measured before taking the shot. All fields are disabled by default. By checking to ON, the FIELD Conditions boxes turn to enabled."

I'm confused on the points you make regarding the BC being calculated/referenced at a ICAO standard atmosphere?

I disagree that this upper field shouldn't be modified, and contend it's use is to capture the conditions that existed when you established the "zero" point for the rifle.

How do you account for how the software knows to make it's correction "from"? No one (well nearly no one I presume) has the rifle "zeroed" under an ICAO atmospheric conditions. It's my contention this field (the top block under Data>Env) is used just as is stated on page 43 and quoted above. It's used to establish the "zero", so the software knows where to make it's correction from.

The BC numbers that shooters are provided have no dependence on environment. That's why we input all our specific environmental data into for our specific application.

I state this from a perspective that is ready to learn, and not one where my way is the right way. I would appreciate it if you'd explain it to me, and others why we should not use this top field to capture the conditions that were present when the rifle as zeroed as per page 42 of the Mobile Users's manual.

Thanks!

 

[Autorotate]

Guys...it's pretty clear to me, right from the horses mouth....

The Data > Env page, top portion of the screen is used to capture the environmental data from your "sight in/zero day".

With all due respect.....The previously mentioned discussion referencing correcting a BC for environmental conditions is misguided....don't go down that road.....on this tab.

Here's my email to Patagonia support:
------------------------------------------------------------------
Date: Sat, May 22, 2010 at 8:53 PM
Subject: LB3 Mobile
To: "[email protected]" <[email protected]>

Sirs

This question pertains to Mobile version 3.0.0.4

Can you provide further explanation as to the proper utilization of the Data > Environment sub-tab in the Mobile Ballistics module?

Specifically, can you address if the following technique is correct:

1. The top portion of the screen should be utilized to capture the appropriate environmental data during the conditions when the rifles "zero" point is established.

This data from your "zero day" should be further supplemented by Data > Sight-In page.

2. During subsequent engagements, under varying conditions, the Field Conditions is ON button should be checked, to permit for the input of appropriate environmental data that my differ from the original zero day conditions.

There was a position/contention made that because a BC of a certain projectile was calculated using a ICAO standard atmosphere, that the top portion of the Data > Env screen should contain the parameters of a ICAO standard atmosphere.

I felt as though this is incorrect, as the BC value that shooters are provided, it would incorrect to correct the BC value for varying environmental conditions.....this is what your wonderful ballistic engine does for us.

All BC values provided to shooters from reputable sources should already be referenced to an ICAO atmosphere....correct?

Can you confirm?
----------------------------

The response-
---------------------
From: Support - Patagonia Ballistics <[email protected]>
Date: Sat, May 22, 2010 at 9:05 PM
Subject: RE: LB3 Mobile
To: Autorotate

Dear Mr. Autorotate,

1) Sight-In (SI) conditions must reflect the current environment conditions present at the moment of sighting-in your rifle/ammo/scope system.

While it's true that LB3D/M atmospheric model is based on the ICAO Standard to effectively use it, your BC must reference the same standard.

So, if you know that the available BC is US ARMY/STD METRO based, then convert it to ICAO before using it. That's a MAJOR cause of bad predictions, since there is no way any program can tell the reference by itself.

However, that's not related to the data a user inputs for the SI Conditions. (I added the emphasis on the quoted sentence for clarification)

2) The Field Conditions (FC) are required to account for, since the True Zero Range (TZR) shifts along the LOS as conditions change.

3) If a program does not account for SI/FC differences, then the ZR will not shift AND both the SI curve and FC curve will share the same ZR. Which is WRONG.

4) Of course, that's important since SI/FC accounts for the "parallel path curve" that's created. Be aware of how a program computes that! Many don't while some are incorrect, creating the false impression of making the differentiation, while in fact they are not shifting the TZR.

5) One way to mitigate the effects of a shifting TZR is having a short ZR, typically 100 yards or so.

6) But if FC conditions are notably different from SI and the ZR is long (about 300 yards or more) then take into account the FC setting or at long range things will get for worse.

7) In short, if you care about LR predictions, then record your SI and enter the actual FC before taking the shot.

8) It's very easy to verify the SI/FC "parallel path curve" by using two tracks and the Graphs tab.

9) If no FC are established, then the predictions will take the SI conditions as the current ones, and the output will yield the corresponding ballistics curve for that environment set.

10) Some manufacturers publishes the BC reference, some not, which is quite unfortunate to say the least.

11) On page 74 (Mobile User's Manual code version 3.0.0.4) there is a chapter entitled "Ballistics – New Environment" which sheds more light on this matter. If not, please get back to us.

12) Your concepts on points 1) y 2) are 100% right.

Thanks!

PB
------------


There may be some confusion on mixing two valid points.....


The input/data entry of changing environmental conditions, and the extensive BC testing Phorwath did.



LB assumes your BC is referenced to a standard ICAO atmosphere. If it's not, LB has a utility that will allow you to convert your BC from whatever environmental conditions it was calculated at, and then convert it to a BC for a ICAO atmosphere.


This may be where Phorwath was confused, as he was calculating BCs using the extended distance chrono method, and then having to correct the "BC" he computed from his field conditions to a ICAO atmosphere "BC".


As stated above by Patagonia, the Data > Env tab isn't the place to do that.


Please correct me if I'm misguided here, and I did not intend to put words in anyone's mouth here...just picking through the thread trying to sleuth were it went wrong.



Hope that helps! gun)

 

[bigngreen]

Just to keep the numbers fresh. At the beginning you had a Station pressure of 25.63 Broz, in the last post you had it changed to 25.3.

So. could you confirm the most accurate data for the day that is a known, this is what I come up with.

300 gr Berger bullet with a G7 BC of .455 and using .500 for a drag.

Clicks are at .250 with a sight height of 2.1.

Sight in is at 300yrds and is .5 in high.

Environmental is a Station pressure of 25.63, a temp of 75* and a Humidity of 30% @ 300 yrd sight in.

1000yrd target was shot @ a temp of 68*

The unknown is the Muzzle velocity.



So I re did my Loadbase tract to these numbers and used a MV of 2750 and I get 20.1MOA for a come up. If I go to a MV of 2740 I get 20.3 MOA. I would guess your MV somewhere in the 2750-2740 range. We will get to do this all over again when you get a chronograph and don't get 2750 fps

The data in these threads kinda gets out of wack and you have to update it to keep it accurate!!!!

 

[bigngreen]

Autorotate, that seems clear to me and is most helpful, you won't get that kind of support any where, Gus I top notch and Loadbase is top of the line, IMHO

 

[Autorotate]

BNG

I agree on all you said on LB...top notch product and support.

I personally don't even think a chrono is needed to solve this mystery for Broz. He/his rifle are shooting so straight, that if he can confirm:

1. His zero height
2. Scope adjustment precision (i.e. at 200 yards how far does the POI shift as measured on a paper/steel target when 80 clicks of adjustment are made on the scope)
3. His sight in conditions

Broz has already killed way out there, is obviously making good ammo, has the requisite shooting ability, and has a straight rifle.

In my mind, if he was to confirm the above three, I'd take the reverse calculated muzzle velocity value that Loadbase would come back with over a chrono velocity in this situation any day of the week. Good shooter/rifle/ammo and a known proven dope trump a chrono in my book.

But a good chrono will help

 

[Pdvdh]

I've also corresponded with Gus and received a similar response to the one received by Autorotate. Gus probably saved time by 'copying and pasting' his response to me to Autorotate. Or vica versa.

So I haven't fallen off the map. I'm engaged in one more round of correspondence with Gus in the effort to come to grips with the instructions Gus intended to be used to develop and save Tracts using LoadBase ballistics software. I'll provide some further input/clarification on my prior Posts after hearing back from Gus.

I differ on the position that field drops are an equivalent, or better method, to establish MV than the chronograph. If you're doing everything else correctly with LoadBase 3.0, then an accurate MV input is the key to accurate long range dope predictions. I know some advocate relying on field drop data to infer a BC or MV. It's true that if one develops a good drop chart at a known set of environmental conditions, that that drop chart can be good-to-go under those environmental conditions, without any chronograph, known MV, or even known atmospheric conditions. Because atmospheric density generally doesn't change so greatly from day to day to cause a miss if one remains at the same elevation. However, having and entering good, accurate data into an accurate ballistics program will allow for accurate predicted dope under any future atmospheric conditions, angled shots, differing elevations, tropical depressions, or high or low pressure systems, and account for spin drift and coriolis affects as well.

Gus has shared some comments from the U.K. military with me in the past which is slightly contrary to the approach of estimating MV base on BC and drops. LoadBase is in use by some portion of the U.K. military. Feedback from those troops is that all they really desire is an accurate MV. With a good MV, they're close to the point of skipping the field-proofing of their LoadBase predicted drops on targets in the field. They've employed LoadBase software enough times to become satisfied that their dope will be good, provided they have entered an accurate MV.

Even with an inherent potential error factor of 0.2% (this value extracted from Oehler), I still believe a quality chronograph used to establish MV is a better MV value for input to LoadBase software than a MV back-estimated from a manufacturer specified BC and measured drops in the field. If you hunt the same elevation and locations day to day, maybe it's less important. But my hunts take me from sea level to 7000 ft elevations, and angle (inclination and declination) shots are common at long range in the mountains I frequent. Under these variable elevations and atmospheric conditions, when I typically have no opportunity to pre-develop and prove field drops, I enjoy the confidence derived from good data in - good predicted drops out with LoadBase 3.0

 

[Pdvdh]

OK,
I've corresponded with Gus and he's confirmed that my method is unorthodox, and not his intended or recommended method of developing and saving Tracts with LoadBase 3.0

I did verify with Gus that the Tracts I developed with my "unorthodox" approach are valid Tracts, with respect to yielding accurate predicted ballistics from the LoadBase software. However the methods I used and described uneccessarily complicate the process of developing and saving Tracts. I'm going to end any further description of my former process, because there is a simpler, more straightforward, method for developing and saving Tracks.

Broz, if you saved a Tract using the method I described in prior posts, it will be a good Tract. However here's how I'd proceed for the development of future Tracts:

One does need to ensure that the BC value used in LB3 is referenced to ICAO Standard Conditions. According to my LB3 User's Manual, Berger's BCs are, so you should be good running the Berger G7 BC. Sierra's BCs are not referenced to ICAO SCs. There's a straightforward math process provided in the LB3 User's Manual that can be used to convert Sierra's BCs in order to obtain a modified Sierra BC referenced to ICAO Standard Conditions, which can then be input into LoadBase 3.0.

Using the Berger G7 BC, enter the proper input values in the Ballistics Module under the Data - Sight-In tab/screen. Ensure that the status box in the Data - Env screen is 'FIELD Conditions is OFF". Enter the actual atmospheric conditions from your Kestrel in the top half of the screen, above the 'Field Conditions is OFF' status line. These will be different than the ICAO Standard Conditions, unless by a real fluke of coincidence, your Kestrel reported values of station pressure, temperature, and humidity happen to be an exact match to the ICAO SC values. Now, with your sight in range and POI in-hand, enter your point of impact in the Data - Sight-In tab/screen in the Zero Height input box, just beneath Zero Range input box. Zero Range in your example was 300 yds. Then go to the Database - TR-Store tab/screen, enter the information to describe your Track's Cartridge, Description, and Firearm, and click "save" in order to save the Tract to the LB3 Database.

Now, in order to use that saved Tract to obtain predicted dope for any new set of atmospheric conditions, recall that Tract from the LB3 database. Ensure that the status box in the Ballistics - Data - Env screen is clicked to 'Field Conditions is ON'. Your sight in environmental conditions should already be visible in the top half of this screen. Enter the current (Kestrel) atmospheric conditions in the lower half of the Data - Env screen, below the 'FIELD Conditions is ON' status line. Then go to the Shoot! - Fire Solution tab/screen, enter your yardage, select MOA (or whatever your preference) at the top of the screen, and presto! The corrective dope for the yardage entered should appear.

If you're going to incorporate Spin Drift and Coriolis corrective dope, then prior to entering the Shoot! - Fire Solution tab/screen, you'll need to open the Data - Drift tab/screen and enter the Azimuth (direction of fire) and Latitude (to obtain Coriolis dope) and the Stability Factor (SG) for your bullet and barrel's twist rate (to obtain Spin Drift dope). The Stability Factor is calculated in the Analyzer Module within the Twist - Data & Results tabs/screens.

Hope this helps and that "alls well that ends well". This is the way I will develop Tracts in LoadBase 3.0 in the future. To my current understanding, this is how Gus intended the LB3 software be used to develop and save Tracts. Using this method is a little simpler (avoids the need for one iterative step) than the one I originally described. You should end up with the same MOA corrective dope using this method as you did with the Tract you developed and saved using the methods I described in my prior posts. If not, we need some more back & forth Posts.

 

[Eaglet]

I can't believe I was so late to the dance. Well, looks like all is good now!

Just some extracts that are good to keep in mind. Notice that Barns, Hornady and Sierra have metro based BCs and when using LB3.0 you need to convert those BCs to ICAO by doing what it says on the third paragraph.