Ballistics beyond 2000 yds : do we need/trust them?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Gustavo, Jan 28, 2007.

  1. Gustavo

    Gustavo Writers Guild

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    From the reading of so many posts about discrepancies in downrange figures from different programs ( commercial or free ) and being myself involved in the development of another package (now in beta) I asked myself : do we need to compute values beyond the 2000 yards mark?

    While with my own knowledge and experience in LRH and ballistics fired a fast answer that doing so is futile due to innacuracies in the math models, especially at the transonic level, and not counting shooter's error at that distance and the almost ever present wind, my guess is that we cannot trust or need to push the envelope that far. Maybe for marketing reasons.

    We have different drag models, differents algorithms, different books...(Pejsa, McCoy, just to name a few) etc, but so far I've never obtained from a certified source a true table showing real vs. predicted values. Not even in military circles, except ( and cannot confirm ) the ones involved in the CheyTac system.

    Moreover, if we take that project into the scene, I've never found any proof of some claims ( and please do not take this statement as it not being possible or unreal )

    In short, when some programs shows downrange values beyond 2000 yards, my best educated estimate is that they rarely are confirmed by real firings.

    A couple of weeks ago I had the opportunity to check during a sniper exercise (Marines' Special Forces) under "somewhat" controlled conditions and up to 1200 yards the values I'm obtaining from my software.

    Well, fortunately drop values were almost near the 99% of the threshold of accuracy ( field data vs predictions ) but when I tried to push the range out to 2000 yards, an experienced officer and a LRH himself, pointed out the many variables involved that otherwise can put in jeopardy a military operation, by not hitting the target with the first or two rounds. Beyond that they call in close air support /ubbthreads/images/graemlins/smirk.gif /ubbthreads/images/graemlins/smirk.gif

    So, they don't need or foresee a future need for tables beyond that range. That prompted my original question posted here.

    In short, I'll like to hear from more experienced shooters waht they think on this subject.

    Thanks in advance!
     
  2. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    In my opinion, the main reason for the inconsistancies has more to do with the rounds being used at these ranges more then anything.

    Take a 308 win.

    Load a 168 to 178 gr match bullet to 2500-2600 fps and look where she drops below supersonic velocity anywhere from 1300 to 1500 yards depending on the elevation your at.

    Some say that some bullets will remain consistant through the transsonic velocities. That may well be but every bullet to some degree will be effected in some way dropping out of supersonic velocity and seldom is there sustained level of predictable consistancy.

    With the 300 Win Mag with a 220 gr smk at 2700-2800 fps and even with this added performance level you will be dropping out of supersonic velocity in the 1500-1700 yard mark.

    The big 338 Lapua and 338 Edge will flirt with the 2K yardage in certain elevations with supersonic velocity but in many cases they will even be on the marginal velocity limits.

    So to answer your question, do we need these predictions with most conventional rounds, probably not simply for the reason that most conventional rounds will not give you super sonic velocity to anywhere near this range and as such consistancy is such that it is nearly impossible to predict what that bullets ballistic personality will be as it drops through and below supersonic velocity.

    Now take the really big 338 rounds based on the 408 CT case and in most environments you will get super sonic velocity out to the 2600 yard range. and in most areas over 2700 yards worth.

    For these, yes they are useful but there probably are not enough of them out there in use yet to make it worthwhile.

    I can tell you for a fact, in good shooting conditions, holding 1 moa out to 2500 yards is not a problem with this class of round. The problem is that if conditions are not ideal, you will play hell getting any kind of consistancy at these ranges.

    Just my opinion.

    Kirby Allen(50)
     

  3. Len Backus

    Len Backus Administrator Staff Member

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  4. Buffalobob

    Buffalobob Writers Guild

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    [ QUOTE ]
    otherwise can put in jeopardy a military operation, by not hitting the target with the first or two rounds. Beyond that they call in close air support

    [/ QUOTE ]

    This man is an idiot and has never been in combat with snipers. I suggest if this is the type of people you are getting information from then your program will be just one more piece of computer code that breaks no new ground. I assume you posted the question to see if there is another side of the story.

    I have to go and do something this morning and I will be back. When I get back I will back up what I said with proof if you wish.

    In the meantime I would just say that this is the second time you have said you are a long range hunter and I would like to see some pictures of the Argentina country side and some animals. If you have no animals to show,at least let us see some country side.
     
  5. CatShooter

    CatShooter Well-Known Member

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    Gustavo...

    I agree with what Buffalobob and Fiftydriver said.

    First, there is no "ONE" military framework that a mil-sniper shoots in.

    Under some conditions, if a military sniper cannot make a first shot hit a 500yds, he will not take the shot... the target at that range might be availably only through a small window or port.

    But under other conditions, snipers can harass enemies at very long range without being at risk - consider that snipers can keep the enemy from drinking water, from using the facilities, getting to the chow tent, just by raining accurate fire on the camp from 2000+yds, even if the hit ratio is &lt;20%.

    Being stuck in a fox hole for three or four days is VERY demoralizing.

    In WW2, the Germans kept our guys dug in for days at a time, and it cost us dearly. We had NO snipers to shoot back, and iron sighted Garands were no match for the German K98 sniper rifles.

    I think your marine friend didn't have much practical experience. Probably a yuppy who didn't get into college /ubbthreads/images/graemlins/wink.gif

    As to the civilian side of things... there is a fellow that was written up in Precision Shooting a few years back that shot a 308 (Ackley) at 3000 yds, and rang steel plates on a regular basis. He used a custom built scope mount with 7 degrees of tilt. He had NO problem with transonic velocities (transonic problems disappear with proper twist rates). He shot a prairie dog at that range - third shot.

    There are folks that whack away at rock chucks at 2,500yds on a regular basis and hit well enough to eliminate "luck".

    I shoot a a 50BMG with 145 moa of up available on the scope, so I think a program that works past 2000yds is just fine.

    So I will vote FOR longer range ballistic software.

    The biggest problem with the current "models" (G1 through G8) is that they are ALL based on artillery projectiles that are 2" to 4" in diameter... and then the data is "scaled down" for us. No one is interested in breaking ground and doing original ballistic work and developing models with a series of projectiles from .17" to .40" at the velocities that we use them.

    So when you punch in the BC for the .224 69gr MatchKing, you are hoping that it will fly "sorta, kinda" like a 4" diameter G7 round... sorta kinda /ubbthreads/images/graemlins/wink.gif

    If you can get accurate predictions of flight to 3000 yds, then go to it. People WILL buy it.

    It's absolutely amazing!! The better your rifle, the better your ammo, the better your flight predictions, and better your ranging capabilities, and the more you practice, the more "luckier" you get /ubbthreads/images/graemlins/wink.gif

    .
     
  6. Michael Eichele

    Michael Eichele Well-Known Member

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    [ QUOTE ]
    In short, when some programs shows downrange values beyond 2000 yards, my best educated estimate is that they rarely are confirmed by real firings.

    [/ QUOTE ]


    What good are my or your firing tests at beyond 2K going to do for anybody else? Unless they shoot the same caliber with the same bullets with the same twist with the same powder and the same primers at the same velocities, firing test only benefit the shooter doing the test.

    As has been brought out MANY times here already, ballistic software will ONLY work for each user AFTER he has done his own tests with his own equipment. From there on, with an accurate BC and drag model for his own equipment, will he get accurate predictions for ever changing enviornmental conditions.

    So to answer your original question. Without doing firing tests for each set of equipment, NO they cannot predict 2000 yard and beyond accuratly. My software cannot, yours cannot, exbal cannot, RSI cannot, sierra cannot. None. It is as simple as that. None ever will be either.

    You must go do firing tests first for accurate predictions in other than your firing test conditions.
     
  7. CatShooter

    CatShooter Well-Known Member

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    [ QUOTE ]
    [ QUOTE ]
    In short, when some programs shows downrange values beyond 2000 yards, my best educated estimate is that they rarely are confirmed by real firings.

    [/ QUOTE ]


    ... Unless they shoot the same caliber with the same bullets with the same twist with the same powder and the same primers at the same velocities, firing test only benefit the shooter doing the test.

    [/ QUOTE ]

    So you say that if I'm shooting a 308 190gr SMK at 3000 fps, and I change powder and primer, and I'm still shooting a 190gr SMK at 3000 fps - my BC and ballistics change, and none of the previously data apply, all because I changed the primer and powder, but the velocity and bullet are the same???

    ... Hmmm that's first in ballistics.

    That theory completely negates all the ballistic work done in the last 100+ years... and makes all the ballistic software useless, because there are no inputs for powder and primer.

    Where did you get that "theory"?

    Inquiring minds want to know /ubbthreads/images/graemlins/frown.gif

    I have been shooting and loading for over 50 years, and started doing velocity measurements and shooting long range in the early 60's... I have never heard of such a "theory".


    .
     
  8. Michael Eichele

    Michael Eichele Well-Known Member

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    The point is catshooter, that in order for my tests to match yours, all things must be equal. That is all the point I am trying to make. Nothing more nothing less.

    Differant powders and differant primers WILL yield differant velocities at differant twists. That is alot of variables. So if I test bullet "A" with all of my equipment, and you test that same bullet with yours, yes the results of BC and drag model WILL be differant.

    Granted, most of the ballistic testing done on record has been done by the military, using VERY similar weapons and load components, so yeah, when using 168's and 175's and othe military match bullets from a 308 with similar twists and similar velocities, things are a little more predictable. Answer me this, when did the military use 178 AMAX's or bergers?? Or when did they use these bullets in a 300 RUM? You simply cannot say that all this ballistic research has been done over the last 100 years and that it is all predictable.

    You say that makes ballistic software usless. If you are trying to hot a target at 1K with out first doing firing tests, youre right. They are useless.

    You have to remember that the point of ballistic software is to accurately predict bullet flight in a new enviornment with real world BC's and drag models. Without those 2 key components, software generates a good guess. YOU CAN ONLY GET ACCURATE BC's AND DRAG MODELS FROM REAL WORLD FIRING TESTS.
     
  9. Michael Eichele

    Michael Eichele Well-Known Member

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    [ QUOTE ]
    So you say that if I'm shooting a 308 190gr SMK at 3000 fps, and I change powder and primer, and I'm still shooting a 190gr SMK at 3000 fps - my BC and ballistics change, and none of the previously data apply, all because I changed the primer and powder, but the velocity and bullet are the same???

    [/ QUOTE ]

    Obviously, if you changed the powder and primer, you wouldnt be shooting the same velocity, now would you?
     
  10. CatShooter

    CatShooter Well-Known Member

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    [ QUOTE ]
    The point is catshooter, that in order for my tests to match yours, all things must be equal. That is all the point I am trying to make. Nothing more nothing less.

    Differant powders and differant primers WILL yield differant velocities at differant twists. That is alot of variables. So if I test bullet "A" with all of my equipment, and you test that same bullet with yours, yes the results of BC and drag model WILL be differant.

    [/ QUOTE ]

    Oh no no no...
    ... you have changed the frame of discussion (and need a spell checker).

    You said that if the powder and primers are different, the results will be different.

    I say, if I shoot a 308 190gr SMK at 3000 fps with purple powder and purple primers, and my friend shoots a 308 190gr SMK at 3000 with red powder and red primers - THE SAME BULLET LEAVES THE MUZZLE AT THE SPEED - they will NOT have different BC's

    External ballistics is the science (art?) of the bullet's flight AFTER it leaves the muzzle. BC's don't play inside the barrel, or at the time of ignition. BC's take over when the bullet breaks free and starts digging it's way through the soup of atmosphere to get where we "hope" it will get.

    I want you to explain how the primer and powder change the BC? It is a simple question.

    That is not asking too much, is it??

    .
     
  11. Gustavo

    Gustavo Writers Guild

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    Gentlemen, thanks for the input!

    But my point was not intended to open a discussion on snipers and their skills...or combat situations. Or to make a point on lucky shots or gifted individuals.

    My point was (is) if we already know that predictions beyond 2000 yards are very unstable, why do we need or trust them?

    Is there a point in making software to generate values beyond that range or is it pointless?

    I of course, can acknowledge the need for such a software ( will market well ), but just to be grounded...who can trust them enough?

    I agree, that every system is unique in its own terms, and that there are many variables involved that can make difficult to match firing tests between different systems.

    But the keywords here are "enough predictive accuracy for cold bore first shots" and when I check the many well-known software packages, well discrepancies of about 50 inches or more are not rare...

    Another view of this post could be, who can give first hand results of shooting "well enough" beyond 2000 yards using which software or math model? I mean with results that matched the program's input.

    PS: to buffalob, yes I love LRH, and Argentina has plenty of places (it's almost an empty country...) with many species, and with so many different scenarios (from the Patagonia, Andes to the deserts) that is almos impossible to give through some pictures a decent impression. Check any tourism website and you might have a good idea or better yet, be my guest and come down here to shoot, I promise a great experience!
     
  12. Eaglet

    Eaglet Well-Known Member

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    CatShooter,
    How the bullet is altered by the internal quality of each rifle will have much to do with your BC. A rough barrel will produce different BC than a custom barrel. Once the bullet has exited the barrel, will have on it markings proportional to the internal quality of a particular rifle affecting, of course, the ability for that bullet to fly. That means our BC for that bullet was changed in the inside of your particular rifle. That's the reason we have to do field testing at different ranges to fine tune the BC for different rifles even if the bullet is coming out of the muzzle at the same velocity.
     
  13. älg

    älg Well-Known Member

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    [ QUOTE ]
    Argentina has plenty of places (it's almost an empty country...) with many species, and with so many different scenarios (from the Patagonia, Andes to the deserts) that is almos impossible to give through some pictures a decent impression

    [/ QUOTE ]

    Yes sir.- I hunted in an area close to Bariloche in the pre-andinean range.... tough hunting, nice place and big red deer too ¡¡
     
  14. CatShooter

    CatShooter Well-Known Member

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    [ QUOTE ]
    CatShooter, How the bullet is altered by the internal quality of each rifle will have much to do with your BC. A rough barrel will produce different BC than a custom barrel.

    [/ QUOTE ]

    I don't know why it is so hard to answer this question without changing the frame work.

    I am referring to the statement that powder and primers will change the BC... there was NOTHING SAID about rough barrels vs smooth barrels. Duh!!

    Why is it so difficult to answer this one statement??

    Lemme try it AGAIN. How does the powder and primer change the BC, if the bullet is exiting the same velocity FROM SMOOTH BARRELS (OK??).

    .