Question for Bryan Litz and Emil Praslick

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  • Apr 12, 2001
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    We are hosting a 10 part series with Berger and Bryan Litz and Emil Praslick

    If you want me to ask specific questions you can post them here:

    The Articles being referenced in the discussions will be found at Berger, you can find the links in the other posts,


    Ballistic Coefficient (BC) is a measure of external ballistic performance for bullets. The higher a bullets BC is, the less drop, and wind deflection it will have at all ranges for a given muzzle velocity and environment.

    BC is a number that can be used as an input for ballistic solvers to predict trajectories. BC is also used as a selling point for long range bullets so due to this marketing use, sometimes BC’s are inflated or skewed by manufacturers to sell more bullets. As a long range shooter who cares about hitting targets, it’s important to understand the basics of BC so you’re not mislead by marketing hype.

    To be more specific, Ballistic Coefficient is a measure of how well a bullet retains velocity as it flies downrange, in comparison to a standard.
     
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    357Max

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    I would like you to ask them about CG (center of gravity). I don't hear much about it, but as bullets continue to get longer I think it becomes more important.

    Questions:

    1. As a bullets center of gravity moves forward does it benefit ELR transitional potential?

    2. Do they think CG will become published specs for bullets going forward as a way to evaluate and compare a bullets transition stability potential for ELR?
    Follow up: How would you best provide CG data?​
    For example based on 100% scale of bullet OAL (45.5% = CG 4.5% behind bullet CL).​
    Since CG calculation would likely be computer driven from solid modeling, I would think it would be best to calculate based on extending the tip to finite point. This would prevent discrepancies between open tip HP vs plastic tip HP?​
    3. This question is only applicable If the answer to Q 1 is affirmative.
    Would Berger consider adding a machined Copper tip bullet option for ELR applications?​
    Adding a Copper tip would move CG forward more then any current tipped option.​

    All below examples would have a different CG:
    • Berger Hybrid CG?
    • Hornady A-tip CG?
    • Hornady ELDM plastic tip CG?
    • Cutting edge lazer plastic tipped mono CG?
    • Warner Flatline mono CG?

    I think with the added CG data point, especially when combined with sectional density and OAL, patterns would emerge as to a bullets ELR stability potential.
     
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    b2lee

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    My questions for Bryan would be...

    1. I love the quality and consistency of Bergers..... tip to ogive, boat tail to base and base to tip, weight from bullet to bullet measurements but have always found myself retipping bullets to get a consistent meplat. The Hornady A-Tips aren't pointy and they can't (easily) be retipped...but I use them in my 300PRC for a very consistent BC and I'm a believer in shifting the weight of the bullet back a little which has seemed to allow me to better stabilize the 250 grain A-Tips in my 1:9 Twist. What is his opinion on traditional bullets with solid tips, consistent meplats, and shifting more weight to the rear of the bullet.

    2. While the above question can also go to the current move to solids in ELR rounds, what is his opinion on weight distribution of solids versus being able to slide the balance point of the bullet back and forward to find the optimal point?
     

    LawnMM

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    Ask about plans for developing the long range target hybrid line, I think that's what it's called.

    The whole holding a 1% BC variation across different lots is pretty badass. Just thinking of being able to mix bullets from different lots without worrying about consistency issues makes me smile.

    Anecdotally, tried the Berger 109s at the same charge and seating depth as the 105s. Wanted to test the accuracy of the drag curve.

    Put a waterline on a full size ipsc at 1040yds. No warm up, fired about ten rounds to check zero and Chrono. Plugged that in and went for 1040, put 3rds inside 1.5" on the waterline at 1040.

    Consider me sold. That crazy consistency is money well spent!
     

    Matches Malone

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    Ask if we can get a formula for wind gradients. I heard Emil talking about something like that on some gun channel sometime ago. :unsure:

    This question is not a big deal but since we’re here...

    has litz ever quantified accuracy with a anti cant level vs not using one.
     

    BLKWLFK9

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    I'd love to hear if Berger has any plans on making a high BC, fast twist .257 hybrid. Berger has tons and tons of different .264 bullets and many .243. If they would make a .257 hybrid in the 120-135g range, they would only have 1 competitor in that market share, and that is Black Jack. Its really hard to beat the performance of a high BC .257 like the BJ Ace. Fast as hell, and bucks the wind as well as a 147-156g class .264.
     
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    SFeldt

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    When will we see custom drag models for the new LRHT (6.5-.308) in the kestrel?
     

    Dthomas3523

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    I posted this question/s on Berger’s FB, but I’ll post it here to so maybe it finds its way into one of the upcoming podcasts:




    At the end of the podcast, Bryan started to get into the topic of when you have a known muzzle velocity. But didn’t go too much into it.

    Since it’s a hot topic when it does come up, let’s say for example, you are using a magnetospeed or Labradar.

    One camp will say “always use this number as it’s a known”

    The other side “good starting point, but do what you have to, to make the calculator work.”

    Could you guys go into more detail on which side you are on and why when it comes to:

    Using a BC (g1 or g7) where you are able to manipulate the MV *and* the BC

    Using a custom drag model where you only have the option of manipulating the MV

    Bryan’s connection got cut off before he had time to address truing when you don’t have access to transonic ranges. Obviously we know that’s the best practice. But for example, I have ready access to about 930yds.

    So, let’s say for the every man, they can find a way to get to a 1k range. All things being equal, with shooter and rifle capable of proper vertical spread needed, how would you specifically recommend truing with:

    G1/g7

    Custom drag models

    Thanks!
     

    BLKWLFK9

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    I posted this question/s on Berger’s FB, but I’ll post it here to so maybe it finds its way into one of the upcoming podcasts:




    At the end of the podcast, Bryan started to get into the topic of when you have a known muzzle velocity. But didn’t go too much into it.

    Since it’s a hot topic when it does come up, let’s say for example, you are using a magnetospeed or Labradar.

    One camp will say “always use this number as it’s a known”

    The other side “good starting point, but do what you have to, to make the calculator work.”

    Could you guys go into more detail on which side you are on and why when it comes to:

    Using a BC (g1 or g7) where you are able to manipulate the MV *and* the BC

    Using a custom drag model where you only have the option of manipulating the MV

    Bryan’s connection got cut off before he had time to address truing when you don’t have access to transonic ranges. Obviously we know that’s the best practice. But for example, I have ready access to about 930yds.

    So, let’s say for the every man, they can find a way to get to a 1k range. All things being equal, with shooter and rifle capable of proper vertical spread needed, how would you specifically recommend truing with:


    G1/g7

    Custom drag models

    Thanks!

    I was hesitant to comment on this, but if you have listened to my podcast, you know I just can't stfu.

    Agreeing that you can true MV at 500ish and BC at 1kish and not having to get all the way out to trans sonic would go against the AB kestrel doctrine that he among the rest have been telling the consumer. Same goes for "Your MV from your labradar and V3 mag is a good number, roll with it." That would fly in the face of what AB has been telling the user for quite some time. Speaking from my personal experience and my experience only, ive never been able to get known dope to line up in AB without drastically lying to with my MV that is verified, and big BC jumps. I can get it to line up, I just have to put in bad data to get it to do so. Maybe AB can't be reliably lined up without going to trans sonic, but I know every other program ive ever used lines up no problem with little to no "fudging numbers." 4Dof for example. For my dasher running a 105Hybrid, I put in my correct MV to the digit, then bumped the axial form factor down .01 and I was lined out all the way to 1125 yards. No real "truing" to it. Its been the same for a number of other bullets as well. Strelock Pro, Shooter, and Trasol. Correct MV and maybe move BC at most .05 up or down, bam.. done. I think Bryan is definitely an authority on the subject and has forgotten more than I will ever know when it comes to ballistics, but I can only speak from my own experience. I know there are millions of shooters out there who love AB. For every person running any other ballistic software, I bet there are 3 using AB. Im aware of that. But I know I can't be the only one that has had this issues with AB.
     

    Dthomas3523

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    I was hesitant to comment on this, but if you have listened to my podcast, you know I just can't stfu.

    Agreeing that you can true MV at 500ish and BC at 1kish and not having to get all the way out to trans sonic would go against the AB kestrel doctrine that he among the rest have been telling the consumer. Same goes for "Your MV from your labradar and V3 mag is a good number, roll with it." That would fly in the face of what AB has been telling the user for quite some time. Speaking from my personal experience and my experience only, ive never been able to get known dope to line up in AB without drastically lying to with my MV that is verified, and big BC jumps. I can get it to line up, I just have to put in bad data to get it to do so. Maybe AB can't be reliably lined up without going to trans sonic, but I know every other program ive ever used lines up no problem with little to no "fudging numbers." 4Dof for example. For my dasher running a 105Hybrid, I put in my correct MV to the digit, then bumped the axial form factor down .01 and I was lined out all the way to 1125 yards. No real "truing" to it. Its been the same for a number of other bullets as well. Strelock Pro, Shooter, and Trasol. Correct MV and maybe move BC at most .05 up or down, bam.. done. I think Bryan is definitely an authority on the subject and has forgotten more than I will ever know when it comes to ballistics, but I can only speak from my own experience. I know there are millions of shooters out there who love AB. For every person running any other ballistic software, I bet there are 3 using AB. Im aware of that. But I know I can't be the only one that has had this issues with AB.

    I’ve had really good luck with AB. Custom curves and BC, without having to adjust too much.

    That being said, I don’t mind lying to it a ton if I have to and it lines up with my real world data.

    But, I’d like to see AB address the everyday shooter who either A) doesn’t have access to transonic range or B) can’t hold their vertical that far out to actually true data

    Not to mention it’s rare in a practical match to be transonic. So unless a shooter has a range pretty close by with that distance, they likely won’t be looking to travel several hours just to attempt to true the way AB would like.
     
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    BLKWLFK9

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  • Feb 13, 2017
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    Yea, I feel you. If lying to it a ton lines it up for that day, that's fine. I just feel that it wouldn't stay as true when the location or environment where to change. Like, that data is good for "right then" but maybe not good for next month, 800 miles away. Maybe just inputting correct data and have a verified drop gives me the warm and fuzzies or something. Like i said, AB is probably the most popular and most used software out there right now. It must work for most.
     

    Jack Master

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    Question for the fellas.

    As the bullet enters the barrel, is the bullet squeezed and elongated? Does this change the bullet's BC for flight from what is was before entering the barrel? Have you done testing on tight or loose bores to know if the Bullet BC could be different for bore condition?
    Does having a tighter bore create more velocity? and is the flight BC better due to this increased velocity?
     
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    Zatchmo

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    I would like to hear the rest of what Brian had to say about truing, but also some discussion about aerodynamic jump, and how the compensation for it is or is not flawed in the kestrel applied ballistics implementation. That last part could be a bridge too far, but the phenomenon itself is interesting.
     
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    Agreeing that you can true MV at 500ish and BC at 1kish and not having to get all the way out to trans sonic would go against the AB kestrel doctrine that he among the rest have been telling the consumer.
    Interestingly, in that podcast, he gave the exact reason for truing velocity at 500-600 yards. He said that velocity is the main determiner of trajectory in the flattest portion of a bullets trajectory...and that generally equates to 500-600 yards. Yet, just a bit later, says transonic around 800 yards.

    You aren't the only one that has had trouble with AB. I switched to an android phone, and the only ballistic app I repurchased was Strelok Pro. The BC banding might be inelegant, but it works extremely well. It typically amounts to nothing more than dropping the BC by 5% once the velocity drops to 1900fps. This gets me all the way to 1200 yards with my 308.

    I did down load 4DOF, just because it is free. It works reasonably well as long as the bullet is actually in the library. 4DOF bugs me because it gives too much spin drift and you can't turn it off.
     
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    BLKWLFK9

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    Interestingly, in that podcast, he gave the exact reason for truing velocity at 500-600 yards. He said that velocity is the main determiner of trajectory in the flattest portion of a bullets trajectory...and that generally equates to 500-600 yards. Yet, just a bit later, says transonic around 800 yards.

    You aren't the only one that has had trouble with AB. I switched to an android phone, and the only ballistic app I repurchased was Strelok Pro. The BC banding might be inelegant, but it works extremely well. It typically amounts to nothing more than dropping the BC by 5% once the velocity drops to 1900fps. This gets me all the way to 1200 yards with my 308.

    I did down load 4DOF, just because it is free. It works reasonably well as long as the bullet is actually in the library. 4DOF bugs me because it gives too much spin drift and you can't turn it off.

    Makes me feel better about my experience with AB hearing that you of most people have had similar luck with it. Lol.
     

    lowlight

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    The point isn’t to get into debates with Bryan, we both are pretty set in our ways, so while it could make compelling radio to enter into discussions of this type, it’s not where my mind is

    I think one of the reasons he defaults to transonic is, his program is written that way. I don’t think he will contradict a built in methodology even though many of us hack the system. we may have adapted, but it’s meant to work as he describes.

    I can have him look at this, but you won’t see me pushing the issue, sure the differences would be fun, but for me, its bad form in this context. People already believe I have issues with him, but I generally like and respect Bryan so I don’t want to appear combative. Our differences in opinion are just that nothing else.
     

    Diver160651

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    I have seen AB's delivery of what works mature over the years. I can honestly say, I have been in disagreement with some of what I heard in the very early days from what I saw as a layman (not a scientist), really into ELR.

    But, I think Bryan has always been the smart guy in the group, but marketing sometimes clouded the waters. Either way, he is a significant contributor and worth our support.

    Here is the thing, we all change our tune as we grow and get more data.

    I am in.. I think it is brilliant to have Bryan on a multi-part podcast, so his snippets do not get misinterpreted. Way to go Frank; way to go Bryan and AB, we will all be a bit richer for listening.
     
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    morganlamprecht

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    I was hesitant to comment on this, but if you have listened to my podcast, you know I just can't stfu.

    Agreeing that you can true MV at 500ish and BC at 1kish and not having to get all the way out to trans sonic would go against the AB kestrel doctrine that he among the rest have been telling the consumer. Same goes for "Your MV from your labradar and V3 mag is a good number, roll with it." That would fly in the face of what AB has been telling the user for quite some time. Speaking from my personal experience and my experience only, ive never been able to get known dope to line up in AB without drastically lying to with my MV that is verified, and big BC jumps. I can get it to line up, I just have to put in bad data to get it to do so. Maybe AB can't be reliably lined up without going to trans sonic, but I know every other program ive ever used lines up no problem with little to no "fudging numbers." 4Dof for example. For my dasher running a 105Hybrid, I put in my correct MV to the digit, then bumped the axial form factor down .01 and I was lined out all the way to 1125 yards. No real "truing" to it. Its been the same for a number of other bullets as well. Strelock Pro, Shooter, and Trasol. Correct MV and maybe move BC at most .05 up or down, bam.. done. I think Bryan is definitely an authority on the subject and has forgotten more than I will ever know when it comes to ballistics, but I can only speak from my own experience. I know there are millions of shooters out there who love AB. For every person running any other ballistic software, I bet there are 3 using AB. Im aware of that. But I know I can't be the only one that has had this issues with AB.

    do you have this issue while having a crosswind wind speed 1 value 8+ mph or is it even on calm/no wind days?

    with ws1 zero'd out, my kestrel/labradar/magneto numbers...i never have to adjust very much, but if i add ws1 in there on a 8+ mph day...id never been able to get it to line up without huge changes most of the time

    DOF can move it (depending on your latitude input) and ws1 (Aero J) can move it quite a bit once the winds get up over 10mph...a couple tenths at 4-500 yds is a lot of velocity to tweak out
     
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    BLKWLFK9

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    lol, im in eastern NC. we aint got wind 'round these parts. If putting in actual true data (MV, BC trued on other solvers, etc.) it can be .2-.4 off in elevation. I can get it to about .1 or good by grossly lying to the kestrel on MV and greatly moving the BC up or down.
     

    morganlamprecht

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    lol fair enough...thats interesting tho...i normally run ballistic AE for quick checks/comparisons and to have backup data on my phone and only put my commonly used loads in my kestrel, but they always seem to be within .1 with the same data inputs inside 1200yds (maybe further but i dont normally shoot further to notice)...curious what the difference you see might be
     

    BLKWLFK9

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    lol fair enough...thats interesting tho...i normally run ballistic AE for quick checks/comparisons and to have backup data on my phone and only put my commonly used loads in my kestrel, but they always seem to be within .1 with the same data inputs inside 1200yds (maybe further but i dont normally shoot further to notice)...curious what the difference you see might be

    lol, i wonder the same thing too. The default answer would be "wrong inputs" but..... they aren't. lol . No different inputs than the other 5 or 6 solvers i play with that all seem to work perfectly with my inputs. It doesnt really matter though. Im happy with the 4dof kestrel and strelock pro/trasol for the phone solvers. They never fail me.
     
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    LastShot300

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    But, I think Bryan has always been the smart guy in the group, but marketing sometimes clouded the waters. Either way, he is a significant contributor and worth our support.
    For Bryan marketing always comes first. Heck the guy is regurgitating old 3DOF Point Mass and all of a sudden it is the best in the world, when most guys doing true ELR work are aware of its many limitations and the old remedy of tweaking values, even those correctly measured like MV which is crazy from a technical perspective. Truing, on the other hand, is about applying sound number crunching to our gathered and measured data, making it the exact opposite of tweaking.

    I agree, he is a contributor, indeed a solid one, but far from being an innovator when it comes to the science of ballistics.
     

    calshipbuilder

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    Here's my question:

    Is there an inherent ballistic advantage to going to a larger caliber?

    For example a 7mm 190 ATIP, .308 245 EOL, 338 300 hybrid, and .375 350 SMK all have fairly similar BC numbers in the mid to low .8 G1s and can all be pushed reasonably around 2900 fps. Why burn the extra powder and take the additional recoil to put a mark on steel?

    Or, why do we see some ELR shooters go to a .416 when the .375s have just as good or better BCs? Is it just spotting benefits?

    So, excluding spotting benefits and not considering terminal performance, would hit probability increase just by increasing the caliber? With all the advancement in bullet tech lately, it's getting harder to justify moving up to a larger platform when today's 7 short mag can run - on paper - with a 338 Improved.

    Discussion on this has some theories but didn't net any data backed results. I'm wondering if Litz or Emil have any data backed findings they can share from all that drag modeling they've done.
     
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    Mike4837

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    Ok, .30 cal 168 grain question. The classic 168 grain Sierra Match King bullet has earned a reputation for poor performance at longer distances and specifically past super sonic speeds. Is this true of other 168 grain options such as Berger's hybrid or the Hornady ELD-M, or is this characteristic specific to the older designed SMK?

    Part 2 of that is: How does one evaluate the bullet's performance at those longer distances aside from looking at a BC or shooting it past super sonic ranges, which not everyone has consistent access to on a regular basis?
     

    calshipbuilder

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    Ok, .30 cal 168 grain question. The classic 168 grain Sierra Match King bullet has earned a reputation for poor performance at longer distances and specifically past super sonic speeds. Is this true of other 168 grain options such as Berger's hybrid or the Hornady ELD-M, or is this characteristic specific to the older designed SMK?

    Part 2 of that is: How does one evaluate the bullet's performance at those longer distances aside from looking at a BC or shooting it past super sonic ranges, which not everyone has consistent access to on a regular basis?

    1. No, for example the 168 berger hybrid does well through transonic. It has to do with the boat tail. Read more here.

    2. shoot them slow, work out a reduced load (or smaller case) that gets you from above transonic to subsonic within the range you do have. Make sure you have enough twist rate to fully stabilize them at the slower MV.
     
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    seansmd

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    I would like to hear his view on why he models AJ, spin drift, and coriolis, the way he does. No need to argue just highlight many if not most are turning these three off to get accurate results. At least in the distances we mostly shoot.
     
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    Diver160651

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    I would like to hear his view on why he models AJ, spin drift, and coriolis, the way he does. No need to argue just highlight many if not most are turning these three off to get accurate results. At least in the distances we mostly shoot.
    The good news is that, some of the above (AJ - was not even talked about) seem softer in the models today.

    I just heard the podcast and enjoyed it. The thing is G1 or G7 in those days, both severely departed from the models when deep transonic, neither was close to what you might expect when dialing 24-28 Mils. I think there could have been a bit more transparency on that topic.

    looking forward to the next episode.
     
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    Davo308

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    I'd be interested in his thoughts on LIDAR wind reading as an adjunct in extreme long range competition shooting.

    Litz has mentioned it in his books.
     
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    357Max

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    Can find these podcasts somewhere?
    Everyday sniper podcast on the pod beam app. Look for the "no BS BC titles"

     
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    Davo308

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    My great uncle emil died in montana last week.

    We fly fished circa 1985.