Author Topic: MALA SKOLA RUCNOG PUNJENJA BY DEVIJANTNA LICNOST  (Read 420554 times)

Snowman

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Re: MALA SKOLA RUCNOG PUNJENJA BY DEVIJANTNA LICNOST
« Reply #1785 on: July 31, 2019, 02:38:23 AM »
Obzirom da sam Chovjekoljubac + Emocionalac, ovdje dajem detaljno objasnjenje kako ova ....hm .... lepotica ?  radi
TRUING  :  https://www.youtube.com/watch?v=3-aeBiuA1iU

Bitno je da za svaki GUN PROFILE koji imate u memoriji svog Kestrela, izvrshite TRUING.

Truing je u stvari 'peglanje' originalnog balistickog rjesenja, tako da vam vash balisticki program ne izbaci teoretsku, nego STVARNU balisticku putanju. Truingom morate PROMIJENITI originalnu pocetnu brzinu, u pocetnu brzinu koja teoretski daje stvarnu balisticku putanju.

Truing se radi na udaljenosti malcice pred transonicnom zonom, ne u transonicnoj zoni, nego pred ulazak u transonicnu zonu.

Prije nego krenete u truing, morate obaviti ove predradnje :

                - ustanoviti nulu na 100 yardi
                - odrediti pravac do mete + izmjeriti atmosferske varijable
                - ispaliti test grupu
                - izmjeriti nadmorsku visinu ( elevaciju ).

Sad, kad vam je puska perfektno nulirana, mozete krenuti u CRUSH    ...... crush ..... ?

To je akronim za :

Capture direction of fire ..... odredite/izmjerite pravac vatre
Range your distance to target    ..... odredite/izmjerite udaljenost do mete
Update wind direction and speed ..... ponovno izmjerite brzinu i pravac vjetra
Sspin your Kestrel .... zavrtite vas Kestrel ( pazite da ne odleti nekome u glavu )

      ………………. a jel, Sneshko, sto ona vrti Kestrel …… ?    ….. da 'produva' cjevchitze koje 'usisavaju' atmosferske podatke ...

Hit    ...... pogodite metu

I sta dalje ?  ..... uzmete Kestrel u ruke i dodjete na CAL MV za gun profile, taj CAL MV ce vam reci na kojoj udaljenosti, vase ispaljeno zrno ulazi u TRANSONICNU ZONU ( Ameri od milja, transonicnu zonu zovu TRANS ).

U konketnom slucaju ove lepotice s izlakiranim kandzama, njen gun profile veli : 'zrno ulazi u TRANS na 859 yardi'. Onda je ona dosla na RANGE od 800 yardi ( znaci cca 7 % pred TRANSom ). Po AB Solveru, njeno zrno na 800 yardi treba 6.88 Mil elevacije, medjutim test ispaljivanje na 800 yardi, je dalo 6.3 Mil, znaci da je realna putanja 0.5 mil ispod teoretske putanje na 800 yardi.

Onda se je spustila dvije linije nize, na DROP i smanjila elevaciju s ( teoretske ) od 6.88 mil na STVARNU : 6.3 Mil. MV ( pocetna brzina ) je onda s teoretske + ispravne od 2860 fps spustena na 2751 fps. Pritisla je ACCEPT dugme na Kestrelu, i sad ima STVARNU balisticku putanju, koja se bazira na POGRESNOJ pocetnoj brzini. Vjerovatno ima jos dosta toga pogresnoga u tom Gun Profile, ali putanja je 'ispeglana', tj. stvarna, na svim udaljenostima i ....... radnja radi ...... Po Sam Millardu, ovo sto ova lepotica radi je NO-NO. Sam ne mijenja MV ( pocetnu brzinu ) vise od +/- 10 fps. U stvari, ova Lepotica je isla linijom manjeg otpora, jednostavno je lijena da mijenja BC, koji je vjerovatno uzrok razlike izmedju stvarne i teoretske putanje .. ma idi bre bezi ....
   


Obzirom da je putanja 'ispeglana', ova lepotica predlaze da sad TESTIRATE tu ispravljenu putanju, recimo pucate u metu kracu od 800 yardi, pa ako se brojka u Kestrelu za tu udaljenost poklapa s rezultatom na meti, znaci da ste GOOD TO GO.

Interesantno je sta kaze ovaj Baja :            https://www.youtube.com/watch?v=ZpqGljLhhGs
On kaze da ako su sve varijable ubacene u balisticki Solver tacne, onda bi teoretska putanja trebala biti istovjetna stvarnoj putanji. U praksi to nije tako, zato jer su jedna ili vise varijabli pogresne, zbog cega se radi TRUING, tj. teoretska putanja se ispegla da odgovara stvarnoj putanji. Vecina strelaca 'ispegla' pocetnu brzinu, jer je to najlakse, iako dobro znaju da je pocetna brzina, koju su ubacili u balisticki solver, ISPRAVNA. Strelci jednostavno idu linijom manjeg otpora. U 99 % slucajeva, krivac za razliku izmedju teoretske i stvarne putanje je POGRESNI BALISTICKI KOEFICIJENT.


Ovo je stvarno dobar video-klip iz Juzne Afrike : https://www.youtube.com/watch?v=VX3Y6kHIa60
Ovaj momak koristi STRELOK App. Stvarna putanja je bila 0.2 Mil visa od teoretske. Objavljeni BC, koji
je ubacio u STRELOK je bio 0.288, i STRELOK mu je onda izbacio Stvarni BC : 0.366.

Izgleda da je STRELOK popularan u Juznoj Africi : https://www.youtube.com/watch?v=ex8QmxnCv0E


Da vidimo sta kaze Brajko : https://www.youtube.com/watch?v=8e7W86iCT4c
Brajko kaze da ako koristite CUSTOM DRAG CURVE u vasem balistickom softveru, vjerovatno vam nece biti potrebno da radite TRUING, iliti drugim rijecima, kako god okrenete, BALISTICKI KOEFICIJENTI, svejedno G1 ili G7, vam daju balisticko rjesenje, koje se razlikuje od stvarnog, ili da to prevedemo na srbski : Moderna balistika je bacila Balisticki Koeficijent u DZUBRE.

Zbog toga prevodim i ovaj tekst, obzirom da sam Chovjekoljubac i Emocionalac : http://appliedballisticsllc.com/ballistics-educational-resources/custom-drag-curves/

Custom Drag Models
Applied Ballistics ( http://appliedballisticsllc.com/ ) ,
vise od jedne decenije, izracunava Custom Drag modele, koji se koriste u izracunavanju balisticke putanje.
Custom Drag Modeli (CDM’s), za zrna, su mnogo napredniji standard za modeliranje leta zrna, od standardnih G1 i G7 modela.
Trik je da kod CDM, koristite STVARNI, IZMJERENI let zrna, u balistickom Solveru ( programu ).
Posljedica cega je da imate mnogo preciznije izracunatu putanju, narocito u transonicnoj zoni.
Mi ( balkanski geniji iz AB ) koristimo nas state-of-the art laboratorij + pokretni laboratorij, gdje testiramo zivu municiju pod kontrolisanim uslovima ......... hm ..... hm ...... ocigledno, u tim laboratorijama postoji visoka koncentracija MIRISA VAZNOSTI BEOGRADZANA ...

………………………… na ovoj fotki je ilustracija onog o cemu Brajko pricha, tj. ni G1 ni G7 model vam nece dati STVARNU putanju, medjutim, CDM hoce :

 http://www.appliedballisticsllc.com/images2/CDM3.JPG
 
…… ako malo prostudirate gornji …. grafikon .. ?   ……………. primijeticete da putanje izracunate na osnovu G1 i G7 standardnih modela, debelo odstupaju od stvarne putanje na brzinama ispod 1.5 Macha ………………….. ima tu jos nesto, taj isti Brajko, koji je 10-ak godina zamajavao narod, prichom da je G1 sranje neopevano, a da je G7 prava stvar, sad kaze da su i G1 i G7 sranje neopevano, i da je prava stvar CDM.

Poznato je inace, da se Tibor i Brajko ne mirishu, navodno zato sto su se zakacili oko izvesne lepotice u Kikindi, lokalno poznate kao FATALNA MILEVA.

U stvari, ne mirishu se, zato jer Tibor prodaje 'papire' na kojima je odstampana stvarna putanja na 3 RAZLICITE temperature, sto je jeftinije nego da spalite par iljadarki na kojekakve jelekronske dzidze-bidze.


Evo sta dalje kaze Brajko : Beneficije drag modeliranja, su ocigledne, zbog cega mnogi pitaju, u cemu je drag modeliranje razlicito od Balistickih Koeficijenata, i sta to sve znachi ?

  http://www.appliedballisticsllc.com/images2/CDM1.JPG

U ovom tekstu cemo pokusati objasniti kako se DRAG modelira kao SILA ( koja vuche zrno unazad ), i kako se ta sila, ugradjuje u Balisticki Solver - da se dodje do vrlo preciznog proracuna balisticke putanje. Na kraju teksta cemo dati par primjera, aplikacije upotrebe CDMa u Applied Ballistics solveru.



Applied Ballistics je izmjerio i okarakterizirao BC i DRAG Modele za preko 850 modernih zrna. Ti podaci su ugradjeni u Apps, dzidze-bidze i Software, kroz metode kao sto su nash AB Connect™ system.
Ranije su podaci kao BC, stability i dimensional data, za ta zrna, objavljivani u knjigama kao Ballistic Performance of Rifle Bullets – 3rd Edition (Library 720).  Svi ti podaci su takodje, u Digitalnim Bibliotekama, koje koriste  Applied Ballistics programi.  U ovom PDF File-u su izlistana sva zrna ukljucena u te Digitalne Biblioteke :  AB Bullet Library : http://www.appliedballisticsllc.com/Downloads/ABLibrary.pdf

Istorijski, najveci problem u kalkulaciji precizne putanje, je pravilno modeliranje  aerodynamic drag of bullets ( AERODINAMICNI DRAG ZRNA ).  Applied Ballistics mnogo eksperimentuje s ispaljivanjem zive municije, i nasa istrazivanja po tom pitanju, pomalo razotkrivaju misterije leta zrna.
 
Da sumiramo: mjerenje CDM koje radi Applied Ballistics je povecalo preciznost Balistickih Solvera.
U nasim Bibliotekama, smo do sada objavili 815 CDM ( misli se da postoje CDM podaci za 815 modernih zrna, iliti drugim rijecima, batalite Balisticke Koeficijente, za tih 815 zrna, jer je Brajko za njih izmjerio CDM u svojim nepokretnim i pokretnim Laboratorijama, u kojima se osjeca MIRIS VAZNOSTI BEOGRADZANA.


CDM podaci se nalaze u slijedecim PRODUKTIMA :

Garmin Foretrex 701,
Kestrel Elite/Ballistics/Ruger,
Kestrel 4500,
Sig Sauer Kilo 2400,
RAPTAR S,
AB Analytics,
AB Tactical,
AB Mobile (Android),
Rapid Engagement Module I
IBEAM.


Pa da prevedem i najnoviju Brajkovu prichu : http://appliedballisticsllc.com/Articles/ABDOC130_CDM.pdf


                                                          Aerodynamic Drag Modeling for Ballistics
                                                                                                         By Bryan Litz
Part 1: Aerodynamic Drag 101

Aerodynamic drag je od velike vaznosti u predvidjanju long range putanje.
Podaci i metode koji uzimaju u obzir ovu varijablu ( aerodinamicni DRAG ) su stani pani kod long range pucanja.
U ovom tekstu cemo objasniti kako aerodynamic drag utjece na predvidjanje putanje kod streljackog oruzja, i kako je tekao
razvoj drag modelinga, od pocetaka pa do danasnjeg nivoa perfekcije.

Fizika aerodinamicnog drag-a


Neki od vas su chuli ili chitali o G1 i G7 standardnim projektilima i standardnim drag modelima.

...... ovdje se morate vratiti na PDF File i obratiti paznju na Figure 1, gdje vidite G1 i G2 projektile
s pripadajucim DRAG krivama, relativno brzini izrazenoj u jedinicama Mach-a ......

Naravno, pitate se sta je to DRAG kriva i koju stvarno vaznost ima ? Zasto se DRAG kriva spusta, kad se brzina
( izrazena u Mach brojci, povecava ? To nema rezona - sjetite se kad glavu proturite kroz prozor automobila koji ubrzava ).
Logicno bi bilo da se DRAG povecava paraleno s povecavanjem brzine.

Iz Grafa ( Figure 1 ), ocigledno je da je Coefficient of Drag (CD) ( Koeficijent draga ) najvisi kad se brzina projektila priblizi ili
izjednaci s brzinom zvuka ( Mach 1 ). Nakon sto se brzina projektila, povecava iznad brzine zvuka ( Mach 2, Mach 3 itd., Koeficijent draga se pocinje spustati. ...... sad, da ga ne tupimo previse : fundamentalno pitanje je : ZASTO CD PADA, KAKO BRZINA RASTE ?


Kljuc za razumijevanje CD je koeficijent.  Koeficijent ne predstavlja silu aerodinamicnog draga izrazenu u funtama ili nekoj drugoj jedinici.
Koeficijent draga (CD) je samo brojka koja izrazava KOLIKO draga ( sile koja vuce zrno unazad ) ima OBLIK PROJEKTILA na odredjenoj brzini.

Zaostreniji projektili imaju manji koeficijent draga, dok tupi projektili imaju veci koeficijent draga.

Ali kakva je relacija iliti odnos koeficijenta draga (drag coefficient ) i stvarnog draga ( vucne sile ) u funtama ( pounds ) ?

Cijela vanjska balistika ( external ballistics ), se osniva na tome koliko brzine projektil gubi, leteci kroz zrak err. VAZDUH.

Koliko zrno PADA, biva ZANOSENO VJETROM, VRIJEME PROVEDENO U LETU i svaki drugi ASPEKT ( kako to BG-zvuchi .... ) putanje zrna je uzrokovano BRZINOM PROJEKTILA, i STOPOM USPORAVANJA.

U jel'te fis'ci, imamo naziv za promjenu u brzini : AKCELERACIJA. A sta kad imamo obratan slucaj, tj. brzina se smanjuje ? E, pa to se zove NEGATIVNA AKCELERACIJA
    ... sto jes-jes, opasan je taj Brajko  .............

Da bi saznali tacnu velicinu negativne akceleracije zrna, na bilo kojoj tachci na putanji, moramo znati koje sile utjecu na usporavanje zrna.  ........ opasan je Brajko ..... samo Balkan radja takve genije ......


I sad dolazimo na  Newtons second law of motion iliti Njutnov drugi zakon mehan'ke : https://www.youtube.com/watch?v=QJTcgWTs9VE, koji nam jasno kaze : ubrzavanje OBJEKTA jest sila koja siluje OBJEKAT, podijeljena MASOM OBJEKTA.

Nije nikakav problem da ustanovimo MASU OBJEKTA, tj. ZRNA, ono sto je problem, je ustanoviti silu koja siluje taj OBJEKAT, a to je, Cenjena Gospodo : SILA AERODINAMICNOG DRAGA (   the aerodynamic drag force  ).


     .................... kakve genije taj Balkan radja ............ !!!!!!!!

Sila aerodinamicnog draga (  the aerodynamic drag force ) = DINAMICNI PRITISAK (dynamic pressure) x POVRSINA PREDNJEG DIJELA ZRNA (bullets frontal area) x KOEFICIJENT DRAGA DOTICNOG ZRNA (its drag coefficient).

..... lepo, lepo, .............. lepo si to sastavio Brajko, ali ako moze malo jasnije, tj. nismo svi BEOGRADZANI ..........


Paz'der vamo ! :

Dynamic Pressure ( DINAMICNI PRITISAK ) :
Dinamicki pritisak ( Dynamic pressure ) je u stvari pritisak dolazeceg zraka iliti pritisak zraka na prednji dio projektila iliti to bi bio pritisak na vashu njushku, kad vam glava viri kroz prozor jureceg automobila. Jedan vazan faktor tog dinamickog pritiska je
GUSTOCA ZRAKA ( air density ).


Ono sto svaki strelac zna je da Balisticki program mora znati : temperaturu , pritisak i vlaznost zraka err. vazduha
da bi izracunao long range balisticku putanju. Te tri varijable ( temperatura, pritisak i vlaznost ) odredjuju GUSTOCU ZRAKA,
koja onda ( gustoca zraka ) DIREKTNO DELUJE na DINAMICKI PRITISAK na zrno u letu, sto onda uzrokuje  aerodynamic drag, zbog cega zrno USPORAVA. .......


Da bi dobili ideju vaznosti utjecaja gustoce zraka na DRAG, pomislite na to kako djeluje razlika
kad brzo mahnete rukom kroz zrak, a onda isto tako brzo 'mahnete' rukom kroz vodu .... hm ..... hm....
kroz vodu to ide malo teze. Zasto ?

Zato jer je gustoca fluida ( vode ), veca od gustoce zraka. Isti princip vazi kod zraka. Sto je zrak gusci, to daje veci
otpor projektilu koji kroz njega leti. Veca gustoca zraka stvara veci DRAG na zrno, zbog cega zrno brze usporava.

A sad da predjemo na fis'ku  i matemat'ku : DINAMICKI PRITISAK SE POVECAVA NA DRUGU POTENCIJU ( NA KVADRAT ), S POVECAVANJEM BRZINE.
Drugim rijecima, ako DUPLIRATE BRZINU, DINAMICKI PRITISAK SE UCHETVEROSTRUCHI !


    …….  neverovatan podatak !                     ………………………… padam u nesvest   …………….

Ako bi utrostrucili brzinu, dinamicki pritisak bi porastao 8 puta. Da to prevedemo na beogradzanski : Dinamicki pritisak ne raste linearno, nego eksponencijalno …... ......... Ooooooooooooo, kako moja dusha pati zbog toga sto nisam postao BEOGRADZANIN .....
« Last Edit: September 29, 2019, 03:10:39 AM by Snowman »
Kao Chovjekoljupcu, moja misija u zivotu je da vas izbavim iz opakih zamki Guzonja i obasjam vas
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Snowman

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Re: MALA SKOLA RUCNOG PUNJENJA BY DEVIJANTNA LICNOST
« Reply #1786 on: August 31, 2019, 02:39:09 AM »
Jedinica dinamickog pritiska je  pounds per square foot ( funte po kvadratnoj stopi ).
BEOGRADZANI koriste drugu jedinicu za dinamicki pritisak : 1 pound force per (square foot) = 0.047880259 kilopascals.  Da-da, BEOGRADZANI kilopaskalisuju !!!!!!!


Opasni su ti BEOGRADZANI. Mnogo vole matemat'ku i fis'ku :


Technical Appendix

Dynamic pressure
The equation for dynamic pressure (pounds per square foot) is:
𝑞 = 1/2𝜌𝑉
2
Where: 𝜌 (greek letter rho) is the air density (slugs per cubic foot;
standard value is 0.002377 sl/ft3
)
V is the velocity of the bullet (feet per second)
Bullet Frontal Area
The equation for a bullets frontal area (square feet) is:
𝑆 = 𝜋 (
𝑐𝑎𝑙
24 )
2
Where: 𝑐𝑎𝑙 is the bullet caliber (inches)
Aerodynamic Drag
The equation for aerodynamic drag on a bullet (pounds) is:
𝑑𝑟𝑎𝑔 = 𝑞𝑆𝐶𝑑
Where: 𝑞 is the dynamic pressure (pounds per square foot)
𝑆 is the bullets frontal area (square feet)
𝐶𝑑 is the bullets drag coefficient (unitless)

Drag Coefficient ( Koeficijent draga )

Drag coefficient zrna utvrdjujemo ispaljivanjem zive municije.
Ispaljujemo MNOGO zrna razlicitim brzinama ( misli se razlicitim Mach brojkama ) ..... i ..... dodjemo do drag curve ( drag krive ).
Sad, Brajko nece reci kako on to radi, da neko nebi pokrao njegove ideje ......        ....... u stvari, logicki se namece zakljucak da Brajko koristi Doppler radar : https://www.thermaxxjackets.com/doppler-effect-frequency-change/

........ sto jes-jes, opasan je Brajko ..... KAKVE GENIJE TAJ BALKAN RADJA !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!   btw. tom metodom su BEOGRADZANI oborili onaj fantomski + neoborivi avion : https://www.youtube.com/watch?v=nGaqByxE3Mc


Brojke ? Recimo projektil koji leti Mach 3 ( to je 3348 fps u standardnim uslovima ), ima 13,310  pounds per square foot dinamickog pritiska ( dynamic pressure ).

Na Mach 2 (2232 fps) zrno osjeca 5,916 pounds per square foot pritiska, a na Mach 1 (1116 fps), bbbbbb ... bednih 1,479 pounds per square foot of pressure. Naravno, dinamicki pritisak je veci na vecoj gustoci zraka, a manji na manjoj gustoci zraka.

Frontal Area .... to je povrsina projektila na koju djeluje dinamicki pritisak iliti to bi bila vasha njushka koja viri kroz prozor jureceg automobila, tj. Glavonje imaju vecu frontalnu area-u od obicnih smrtnika .....

Dinamicki pritisak se izrazava kao pounds per square foot, znaci da bi izracunali konkretnu brojku
aerodinamickog draga u funtama ( pounds ) - potrebno je da znamo na koliku povrsinu djeluje dinamicki pritisak.
Drugim rijecima, trebamo znati kolika je FRONTAL AREA ( povrsina na koju djeluje dinamicki pritisak ) ZRNA u  square feet.

             ........... square feet je kvadratna stopa ( 1 square feet = 0.092903 kvadratnog metra )


Frontal area zrna, nije neki problem da se izracuna. Recimo frontal area .308 projektila je 0.000517 square feet.

Da bi izracunali drag force ( DRAG silu ili vuchnu silu ) za Mach 1,2 i 3,
jednostavno pomnozimo dinamicki pritisak na svakoj od tih brzina sa frontal area - frontalnom
povrsinom projektila.
Za .308 projektil, te brojke su :

6.9 pounds at Mach 3,
3.1 pounds at Mach 2, i
0.8 pounds at Mach 1
, u standardnim uslovima.

Sad kad znamo pritisak i povrsinu na koju taj pritisak djeluje, moguce je
prikazati aerodinamicnu drag silu za dijapazon razlicitih brzina projektila.



« Last Edit: October 14, 2019, 12:44:35 AM by Snowman »
Kao Chovjekoljupcu, moja misija u zivotu je da vas izbavim iz opakih zamki Guzonja i obasjam vas
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Snowman

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Re: MALA SKOLA RUCNOG PUNJENJA BY DEVIJANTNA LICNOST
« Reply #1787 on: September 29, 2019, 03:12:21 AM »
I tako ...... intelektualno superiorni Homo Balkaniensisi sad dolaze do zakljucka da
dinamicki pritisak koji djeluje na prednju povrsinu zrna - proizvodi AERODINAMICNI DRAG.
Hm ..... hm ......, a ima li oblik zrna utjecaja na AERODINAMICKI DRAG ?

Drag Coefficient ( Koeficijent draga )

Da-da .... sad dolazimo do tacke koja se zove DOSLA GICA U KOLICA. Kako je naglaseno na pocetku,
Koeficijent draga iliti  the coefficient of drag (CD),
je BROJ koji se ubacuje u osnovnu kalkulaciju draga vs OBLIKA PROJEKTILA.
Projektil koji je TOTALNO TUP na vrhu, ce imati Koeficijent draga blizu BROJKE 1 !!!!!!
Zasto broj 1 ? Zato sto ce frontalna povrsina ( frontal area ) TUPOG projektila, uzeti
veliku silu dinamickog pritiska.
Projektil s zakrivljenim nosom i mozda boat tailom ce imati mnogo manji DRAG pri istoj brzini.

.......... sad Brajko ovdje otkriva Jameriku : zasiljeno zrno sporije usporava od tupog zrna .... ? .... ta
nemojte kas'ti ...... to zna i moja Baba ......... ma idi bre bezi ......

 
Da se vratimo sad na Figure 1 : http://appliedballisticsllc.com/Articles/ABDOC130_CDM.pdf.
Vidimo da na Mach 3 (3348 fps), G1 projektil ima drag coefficient  0.51,
dok  G7 projektil ima drag coefficient od samo 0.24.

Spomenuto je vec da na Mach 3, zrno .308 kalibra ima
6.9 pounds of drag na toj brzini ( misli se na dinamicki pritisak na prednju povrsinu zrna ).
Medjutim, to je maksimalni pritisak na TOTALNO TUP .308 projektil.
Realno, moderni .308 projektil koji ima G7 oblik, ima samo 24% od tih 6.9 pounds, iliti drugim
rijecima, moderni, G7 projektil kalibra .308, ima CD od samo 0.24. ...... objasnjeno je vec da
TOTALNO TUPI projektil, ima CD 1.0.       .....


Figure 4. : Stvarni drag razlicitih oblika projektila od nule do Mach 3.
ABDOC130 Copyright © 2016 by Applied Ballistics, LLC. All rights reserved.

 5
There is some minor simplification going on here for the sake of clarity and remaining at
the shooter speak level, but the main ideas are all here. Figure 4 above shows the culmination
of aerodynamic drag including: dynamic pressure, bullet frontal area, and drag curve to account
for projectile shape. If you look closely, you can see where the drag curve plot affects the force
of drag around Mach 1. The steep ramp at this speed is what is referred to as the sound
barrier; the sharp rise in drag as you approach the speed of sound. Most flight vehicles such as
aircraft and rockets approach the sound barrier from the left side of Figure 4, as they accelerate
to higher speeds. Bullets are an exception here, as they are high supersonic as soon as they exit
the muzzle (right side of Figure 4) and spend all their time slowing down to the sound barrier at
Mach 1.
Hopefully this background has shown you how the drag coefficient plots like those in
Figure 1 actually relate to something physical. The following summary will highlight the
important insights you should move forward with:
Summary
 The force of aerodynamic drag is made up of the dynamic air pressure applied to the
bullets frontal area, times a drag coefficient.
 The drag coefficient (CD) scales the drag at each speed based on the shape of the
bullet.
 The drag curve is just the drag coefficient for all speeds.
 The drag curve of a bullet is determined by measuring its drag at multiple flight
speeds; measure enough points at different speeds and connect the dots to make a
drag curve.
It’s important to know what the drag curve is not:
 A drag curve is not a trajectory path for a bullet.
 A drag curve is not a mathematical equation (more on this in the next section).
 A drag curve is not a predictive algorithm



« Last Edit: December 10, 2019, 07:45:56 AM by Snowman »
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Snowman

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Re: MALA SKOLA RUCNOG PUNJENJA BY DEVIJANTNA LICNOST
« Reply #1788 on: October 13, 2019, 12:50:58 PM »
Part 2: Custom Drag Models and Ballistic Coefficients
You may recall from other sources that all projectile shapes have a unique drag curve
based on their shape. Furthermore, bullets within a given class can all be represented with a
Ballistic Coefficient (BC) referenced to a standard curve such as G1 or G7. For more background
on this, refer to Chapter 2 of Applied Ballistics for Long Range Shooting. The basic idea is that
it’s much easier to represent the drag of a class of bullets by referencing all bullets to a
common standard. This is where you get G1 BC’s, G7 BC’s, etc.
The simplicity of the standard curve approach is offset by the compromise that the
actual unique projectile drag is not accurately being modeled for each and every bullet shape.


In most cases, the drag shapes are similar enough that simply scaling the drag curve with a form
factor results in trajectory predictions that are accurate enough. However for the ultimate in
accurate drag modeling, nothing beats the use of Custom Drag Models (CDM’s). CDM’s
dispense with the compromise of matching ‘G’ standards and basically makes every bullet its
own standard by modeling its unique drag. The benefit of CDM’s over BC’s is maximized at
extended range near transonic speeds (near Mach 1). This is where the bullets drag curve is
most unique; each one being like a fingerprint describing how a particular bullet shape makes
its way from supersonic to subsonic speed.
This is the perfect place for a historical footnote.
The use of standard projectiles and Ballistic Coefficients was established prior to the
advent of the modern computer. At that time, firing tables for small arms were computed by
hand. It was very tedious work that sometimes took months to calculate a single trajectory.
During that time, the military (let alone the sporting arms industry) couldn’t make use of
custom drag models due to computational constraints. This is why the standard ‘G’ projectiles
and drag curves were created. By creating tables for only a small number of standard
projectiles, then referencing each bullet to its closest matching standard, reasonably accurate
tables could be produced efficiently. This practice remained common until about the 1950’s
when modern computers enabled the use of custom trajectory calculations in the field. The use
of BC referenced to G standards has continued in the sporting arms industry and much of the
military’s small arms ballistics calculators. Only recently has the modern standard migrated
from the G1 standard to the G7 which is a much better match for modern small arms ballistics.
Why, you might ask, did it take so long for the modern standard to move from G1 to G7?
Furthermore, you might ask, why haven’t we done away with BC’s in favor of CDM’s now that
computational power is no longer a constraint? The answer is two-fold. First, you have the
natural reluctance of people to change and adopt a new paradigm even though it’s better. But
even if people were all gung-ho about changing to the G7 standard, what good would it do if
there weren’t an accurate and extensive library of G7 BC DATA?
Without accurate data, G7 BC’s would just be a good idea with no way to implement.
Recognizing this impediment to progress, Applied Ballistics has gone to great lengths to
test and publish G7 BC’s on hundreds of modern bullets used in long range shooting. The
creation of that accurate and extensive data library, combined with capable computers and
software have enabled the shooting world to take advantage of this better matching G7 BC.
Even as the world embraced the better matching BC, one couldn’t help but wonder why
not go straight to the CDM’s for each bullet rather than accepting another approximation albeit
an improved approximation. The hold up with widespread use of CDM’s was again, availability
of DATA. It’s one thing to generate a G7 BC based on some limited measurements of
downrange velocity or time of flight. But to map out the entire drag curve for each bullet takes
a lot more work! Applied Ballistics has worked tirelessly to complete a library of custom drag
models for hundreds of bullets in its library. These CDM’s are all based on carefully conducted
live fire and represent the most accurate and complete means to model drag for modern
bullets. Below are a few examples of the test firing showing the AB Custom Drag Model
compared to G1 and G7 approximations of drag.
The first plot is for the .243 caliber 95 grain Berger VLD. Each of the blue data points is
an average of multiple shots fired at that velocity. The CDM is determined by measuring
discrete points of drag at various speeds, then sort of connecting the dots to produce a
continuous curve. The error bounds are shown on the measured data points which represent
+/- 2 standard errors. In the case of this bullet, the actual drag is somewhere between the G1
and G7 curves.
If you’ve been paying attention, you’ll recall that in Figure 1 the G1 drag curve was much
higher than the G7, and here they’re shown as nearly equal in supersonic speeds. This is
because the drag curves are scaled to the projectile drag measurements via a form factor. This
is explained in great detail in Chapter 2 of Applied Ballistics for Long Range Shooting.
Below is another example of carefully collected live fire test data, this time on the
Berger .308 caliber 155.5 grain FULLBORE bullet. Note how the drag curve is very similar to the
G7 standard but not quite the same. These subtle differences in drag modeling between the G
standards and the actual drag are the last frontier in eliminating error from modern drag
modeling. With CDM’s you don’t have to settle for the best fitting representation of your
bullet, you can actually model the drag of your specific bullet.

To get an idea of the experimental nature of these live fire tests, consider the following
plot which shows each single data point from the test; each data point representing a single
shot. In the plot below you can see that the data points measured in the live fire test are quite
repeatable and rarely stray far from the average. This plot shows the dense collection of data
points around transonic and down thru Mach 1. High confidence data like this is the best way
to support the most accurate long range trajectory predictions.

Long range shooters who are familiar with ballistics programs are very familiar with the
following phrase: Garbage in, Garbage out. The phrase is referring to the users ability to supply
accurate inputs such as muzzle velocity, range, BC, wind, etc. Although internal to the ballistic
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.50 1.00 1.50 2.00 2.50 3.00
CD
Mach
Berger .308 Caliber 155.5 grain FULLBORE
Measured
G1 Drag Model
G7 Drag Model
AB Custom Drag Model
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.50 1.00 1.50 2.00 2.50 3.00
CD
Mach
Berger .308 Caliber 155.5 grain FULLBORE
Measured
G1 Drag Model
G7 Drag Model
AB Custom Drag Model
ABDOC130 Copyright © 2016 by Applied Ballistics, LLC. All rights reserved. 9
solver, the drag model is sort of like an input. If you input a G1 or G7 BC, the properly written
ballistic solver is scaling and applying the G1 or G7 standard drag curve inside the solver
according to your BC input. Any mismatch between your bullets drag curve and the G1 and G7
curves will manifest as subtle error in trajectory prediction at extended range. However if
you’re using a carefully measured custom drag model to represent the drag curve for your
bullet, then that’s the best you can do.
The combination of: modern computers, ballistics software, and an extensive library of
custom drag models based on live fire have enabled an unprecedented level of accuracy in
long range trajectory prediction.
Part 3: Application of Custom Drag Models
A concept that many long range shooters are familiar with is truing or calibrating the
ballistic solver. This is basically the process of firing shots at long range, telling the ballistic
computer where you hit, so it can self-correct itself. This process is necessary in some
applications where shooters may not have good information on their bullets muzzle velocity or
BC. Muzzle Velocity (MV) uncertainty will always be an issue in such applications and so robust
calibration process are important. However the time of shooting to tweak a BC thru various
velocity bands is over. With Custom Drag Modeling, you don’t have to question the BC or drag
model that your ballistic solver is using because it’s already been done with live fire. The
shooter is free to concentrate on the other unknowns in the environment like MV, range and
wind.
As a user of ballistic software, it’s important to understand the distinction in the various
types of ballistic solvers. Just like G7 BC’s and CDM’s are only useful if the data exists, those
things also require compatible software to properly use that data in a bullet fly-out simulation.
The Point Mass (PM) class of ballistic solvers has been the modern standard for trajectory
computation since the 1950’s when computers became powerful enough to crunch the
numbers. Only point mass solvers are capable of modeling the CDM’s that have been
measured for various bullets. There are different classes of ballistic solvers which solve the
math in ways that prevent them from working with the live fire derived CDM library. For
example, all solvers based on the Pejsa method and similar approaches use mathematical
functions to approximate the shape of drag curves. Using these mathematical functions, it’s
not possible to model the true drag of the bullet as it was measured and represented in the
CDM. A few modern solvers use these methods because they’re easier to program, but there is
no live fire database of BC’s or CDM’s that is technically compatible with non-Point Mass
solvers. Beware of solvers that allow you to bend the drag curve of your bullet; those are
solvers that are not providing solid data for you to begin with and rely on the shooter to
conduct laboratory grade testing to make it accurate.
So how accurately can a ballistic solver using CDM’s predict trajectories at extended
ranges? The following tables summarize some carefully collected data that was fired at
extended range, deep into transonic where trajectory predictions typically fall apart. A short
barreled 308 Winchester firing 175 grain bullets was used to engage targets out to 1323 yards,
which is deep into the transonic range for that bullet. Table 1 shows the observed drop
compared to the drop predicted by the Applied Ballistics PM Solver using a CDM. Note that all
of the predicted data in Table 1 is un-calibrated/un-trued meaning the MV was taken from a
chronograph prior to the test, and not adjusted afterwords to match up with observed points.
Sierra .30 caliber 175 MatchKing
Actual Custom Curve - No Truing
Range Vel/Mach Drop MILS Prediction Error MILS Error Inches
300 2074/1.88 -1.1 -1.09 -0.01 -0.1
600 1627/1.47 -4.3 -4.36 0.06 1.3
1000 1135/1.03 -11.2 -11.36 0.16 5.8
1101 1058/0.96 -13.7 -13.80 0.10 4.0
1166 1025/0.92 -15.5 -15.38 -0.12 -5.0
1200 1010/0.92 -16.6 -16.55 -0.05 -2.2
1323 967/0.87 -19.9 -20.08 0.18 8.6
Table 1. Actual vs. Predicted drop for the 175 grain Sierra MatchKing thru
transonic speed.
Table 1 shows the actual vs. predicted drop for the .30 caliber 175 grain Sierra
MatchKing, fired at an average muzzle velocity of 2570 fps. The observed drop is based on
what was required to center the group on a steel target, so there is some minor uncertainty in
the observed data, maybe +/- 1 click (0.1 MIL). Note that the velocities and Mach numbers
shown in red are indicating transonic range, where the bullet has slowed below Mach 1.2, or
about 1340 fps. This is the range that’s most difficult to predict drop due to the mismatch in
drag curves between the standard G1/G7 and the projectiles actual CDM. Using the CDM to
model the bullets actual flight path results in predictions that are within +/- 9” all the way to
1323 yards which is Mach 0.87 for this bullet.

Berger .30 caliber 175 OTM Tactical
Actual Custom Curve - No Truing
Range Vel/Mach Drop MILS Prediction Error MILS Error Inches
300 2088/1.89 -1.1 -0.94 -0.16 -1.7
600 1660/1.50 -4.0 -4.08 0.08 1.7
700 1531/1.39 -5.6 -5.47 -0.13 -3.3
1000 1182/1.07 -10.7 -10.66 -0.04 -1.4
1101 1088/0.99 -12.8 -12.93 0.13 5.2
1166 1059/0.95 -14.2 -14.43 0.23 9.7
1200 1032/0.94 -15.4 -15.45 0.05 2.2
1323 993/0.90 -18.6 -18.76 0.16 7.6
Table 2. Actual vs. Predicted drop for the 175 grain Berger OTM Tactical thru
transonic speed.
Table 2 shows the same data for the Berger .30 caliber 175 grain OTM Tactical bullet.
Again you can see the CDM prediction matches the observed drop within +/- 10” for the full
trajectory which includes deep transonic flight.
Remember that the tables above are showing the UN-TRUED raw predictions from the
Applied Ballistics solver and CDM’s. In other words; nothing was tweaked to bring these
predictions into alignment with the observed drop. This is the first shot accuracy of the
Applied Ballistics solver when used with CDM’s.
The predictions using the G7 BC were also very close, while the G1 predictions are the
worse. It’s worth noting that Applied Ballistics is the only source of live fire BC and CDM data
for all brands of modern long range bullets. There is no combination of ballistic solver and data
that matches the accuracy of the Applied Ballistics solver when used with Applied Ballistics
CDM’s.
« Last Edit: December 10, 2019, 07:57:48 AM by Snowman »
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Snowman

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Re: MALA SKOLA RUCNOG PUNJENJA BY DEVIJANTNA LICNOST
« Reply #1789 on: December 10, 2019, 07:48:13 AM »

Obzirom da neki Forumasi ovih dana nabavljaju Kestrel 5700 Elite, ,,,,, Tibor kaze da uz njega morate nabaviti jos jednu
igracku : https://www.youtube.com/watch?v=4Ujgbq-Th_Q ................ naravno, podrazumijeva se da imate i ODJE MOBILNI ..... na koji downloadujete SIG SAUERov App. Lepo ...... lepo ....... https://www.youtube.com/watch?v=5hMzjvHvZWI

Ovdje cu napraviti mali intermezzo. Ovo je dobar video za Bracu u Otadzbinama/Domovinama koja stekaju lovu za presu : https://www.youtube.com/watch?v=TqcYI0G2hqM
Kao Chovjekoljupcu, moja misija u zivotu je da vas izbavim iz opakih zamki Guzonja i obasjam vas
neugasivom svijetloscu spoznanja istine.

Snowman

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Kao Chovjekoljupcu, moja misija u zivotu je da vas izbavim iz opakih zamki Guzonja i obasjam vas
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