Is the Ballistic Coefficient Accurate?

[HappyHellfire]

Hi, in a blatant attempt to market for my new bullets (AerospikeBullets.com), I figured I would start a series of posts on the history of ballistics that most people don't know. I have a PhD in Aerospace Engineering and my field of study is ballistics so I have learned some cool things along the way. I also wrote the most recent textbook on external ballistics but don't bother with that unless you're a math nerd like me.

Have you ever wondered where the BC came from and why we use (and misuse) it still today? Why is some bullets use a BC relative to the G7 and some relative to the G1? Go read my article then let's get to discussing if we still should use them.

 

[cuznguido]

Can o worms if ever there was one

 

[HappyHellfire]

These are the drag curves for the two standard projectiles most commonly used for BC (the G1 and G7). The Sierra 168 BTHP is one of the most studied bullets in the world. Why would you compare it to the G1? Sure it makes the number look good but the number is completely useless. The BC compared to the G7 can be used to pretty accurately predict the drop using Siacci Tables (or Ingalls Tables).

 

[HappyHellfire]

Does anyone know the units for BC?

 

[Just Say Moe]

Angstroms?

 

[HappyHellfire]

Angstroms?

I literally had to google what this was!

 

[C.E.Smith043]

There used to be articles in PS magazine like this about midway thru.... I always skipped over them. Just not my cup of tea.

 

[HappyHellfire]

There used to be articles in PS magazine like this about midway thru.... I always skipped over them. Just not my cup of tea.

Yeah, It always frustrated me so I just kept digging and digging to understand it. Then I looked up ten years later and I had a PhD in the subject. If you have to study something that deep, it might as well be something cool.

 

[Just Say Moe]

For sure. I studied a lot of stuff though not near Associates level much less Phd! Congrats!

 

[HappyHellfire]

Does anyone know the units for BC?

In the US and England we use pounds per square inch or psi, just like with water pressure!

 

[HappyHellfire]

In the US and England we use pounds per square inch or psi, just like with water pressure!

But English units are weird. The BC is pounds mass per square inch whereas water uses pounds force per square inch. Europe just uses kg per square meter.

 

[Dave M.]

No offense, but what point are you trying to make, other than to flaunt your obvious PhD knowledge of external ballistics and BCs? Or is this ultimately leading to your post telling us how your bullets are superior to anything on the open market??
Dave

 

[expiper]

if a bullet hits a little low ,,I crank up on my scope,,,,Roger

 

[farmerjohn]

Hi, in a blatant attempt to market for my new bullets (AerospikeBullets.com), I figured I would start a series of posts on the history of ballistics that most people don't know. I have a PhD in Aerospace Engineering and my field of study is ballistics so I have learned some cool things along the way. I also wrote the most recent textbook on external ballistics but don't bother with that unless you're a math nerd like me.

Have you ever wondered where the BC came from and why we use (and misuse) it still today? Why is some bullets use a BC relative to the G7 and some relative to the G1? Go read my article then let's get to discussing if we still should use them.

Welcome to the site, would like to see you become a contributor, $ as well as knowledge.
My wife has a PhD and I often point out to an old redneck farmer it often stands for "piled higher and deeper". As a shooter the math and lingo makes my head hurt, but also on this site are several custom bullet makers that hold a lot of national records in the several disciplines of compition, show us what you got. I figure somebody out of Kentucky will chime in pretty soon...... John

 

[HappyHellfire]

No offense, but what point are you trying to make, other than to flaunt your obvious PhD knowledge of external ballistics and BCs? Or is this ultimately leading to your post telling us how your bullets are superior to anything on the open market??
Dave

Hi Dave,

One of the reasons that the "nerdy academic" side of ballistics is held in so little regard is that it is so difficult to translate the math into a solid initial drop table. I would like to see that change. When a pointy boattail is advertised as a G1 BC and then a shooter plugs that into a ballistic solver and gets garbage results, it implies that the math is wrong.

And yes, my bullets do not follow any of the standard profiles like the G1 or G7. I need to get y'all to start thinking about that and swallow the pill that these new bullets are the next step in rifle shooting.

Maybe I should put a drop table calculator on my website? One that uses drag curves instead of BC?

 

[TylerFromMS]

Show targets. Math is cool. Lots of tiny little groups is cooler.

 

[SecondsCount]

Hi, in a blatant attempt to market for my new bullets (AerospikeBullets.com), I figured I would start a series of posts on the history of ballistics that most people don't know. I have a PhD in Aerospace Engineering and my field of study is ballistics so I have learned some cool things along the way. I also wrote the most recent textbook on external ballistics but don't bother with that unless you're a math nerd like me.

Have you ever wondered where the BC came from and why we use (and misuse) it still today? Why is some bullets use a BC relative to the G7 and some relative to the G1? Go read my article then let's get to discussing if we still should use them.

How does your 146 grain 30 cal bullet compare in performance to a traditional boat tail bullet?

Am I reading your graph correctly is post#3 that shows the BC of a bullet eventually starting to decrease the faster it flies?

 

[HappyHellfire]

Show targets. Math is cool. Lots of tiny little groups is cooler.

 

[shoot4fun]

Hi Dave,

One of the reasons that the "nerdy academic" side of ballistics is held in so little regard is that it is so difficult to translate the math into a solid initial drop table. I would like to see that change. When a pointy boattail is advertised as a G1 BC and then a shooter plugs that into a ballistic solver and gets garbage results, it implies that the math is wrong.

And yes, my bullets do not follow any of the standard profiles like the G1 or G7. I need to get y'all to start thinking about that and swallow the pill that these new bullets are the next step in rifle shooting.

Maybe I should put a drop table calculator on my website? One that uses drag curves instead of BC?

Two things:
1. Hornady needs you. You're their kinda marketing guy.
2. You UID here should be @DRAG-ON.

I wish I had counted all the times someone came to me with an idea that would "change everything" in the firearms industry. When I said no thanks they said I would be sorry because they would sell their idea to a competitor. Well, 99.9% of those "revolutionary ideas" are still not anything but ideas. But the ONE that did get from idea to cocktail napkin to marketed by a competitor failed miserably.

 

[280ai]

What is needed here is a verified side by side test. Your new bullet design against say three of the top bullets same Cal. and weight shot at 500 out of the same gun. Target always tells the truth!