Long range bullets that will penetrate up close without blowing up.

[Greasegun]

Mass=volume x density. Lead has a significantly higher density than copper. Thus leading to higher B.C. with the same shape.


B.C. Calculation is affected by the mass of the projectile.

See above link but here is the breakdown

"The Math / Science
Ballistics is the science of mechanics behind projectile flight, behavior of objects during un-powered trajectories, and the effects of projectiles. Ballistics predicts the flight of objects such as bullets, free-falling bombs, rockets, or similar objects whose path is determined primarily by gravity and air resistance. The ballistic coefficient (BC) of an object defines the effect of air resistance on the object's flight. BC is inversely proportional to the negative acceleration of the ballistic object. The projectile, the ballistic object possesses drag, the BC measures the extend of the drag's effect on the object.

BC is a function of mass, diameter, and drag coefficient and also relates to the aerodynamics of the projectile. Ballistic coefficient has units of mass per area (lb/in2 or kg/m2)"


Imagine throwing a ping pong ball, and a golf ball. Similar in size and shape but very different in weight. Which one will fly further? This is why given the same shape and size, copper bullets will be lighter than lead core bullets, therefore ballistically inferior.

 

[dfanonymous]

The formula compares the weight in relation to the diameter. It's not about the weight itself. Since you can't make the diameter larger, it comes out in length as I said. So in retrospect, it's length, not direct mass. It's weight divided by diameter squares.

The last part I summed up in two words, that's form factor. There are more than one formula for intial calculations to include SD/i (form factor).
BC's are modeled. This is why there are different models like G1 and G7 and some others. These models represent these form factors.

It's just misleading to say mass or weight is a huge contributing factor to BC when its SD=Mass/cross section area. Or simply put in regards to a projectile, length of a particular caliber, which is less confusing.

 

[Greasegun]

The formula compares the weight in relation to the diameter. It's not about the weight itself. Since you can't make the diameter larger, it comes out in length as I said. So in retrospect, it's length, not direct mass. It's weight divided by diameter squares.

The last part I summed up in two words, that's form factor. There are more than one formula for intial calculations to include SD/i (form factor).
BC's are modeled. This is why there are different models like G1 and G7 and some others. These models represent these form factors.

It's just misleading to say mass or weight is a huge contributing factor to BC when its SD=Mass/cross section area. Or simply put in regards to a projectile, length of a particular caliber, which is less confusing.

Sectional density is not used in BC calculation. The formula is actually the BC= mass/Cd*A. Cd= coefficient of drag, A=cross section. The Cd is determined by the shape of the projectile, which is a very important factor. Its impossible to create a copper projectile with the same mass as a lead projectile if the 2 have the same shape (Drag Coeffiecient). So back to my point, copper projectiles BC will never be as good as lead, unless it had a more efficient shape.

 

[dfanonymous]

Sectional density is not used in BC calculation. The formula is actually the BC= mass/Cd*A. Cd= coefficient of drag, A=cross section. The Cd is determined by the shape of the projectile, which is a very important factor. Its impossible to create a copper projectile with the same mass as a lead projectile if the 2 have the same shape (Drag Coeffiecient). So back to my point, copper projectiles BC will never be as good as lead, unless it had a more efficient shape.

Dude, I don't think you understand the math. The pic is straight from Bryan litz's book. He uses w/7000 / cal^2 x i
I've already listed the i, the w/7000 can be rewritten in more school like form of pi x radius^2. It's about the same thing but with the conversion of weight when doing the math. It's literally the formula for SD.


Here is this.

Form Factors: A Useful Analysis Tool

In 2009, Berger Bullets introduced G7 BC’s for boat tail bullets. For those who are unfamiliar with G7 BCs, it’s simply a Ballistic Coefficient referenced to the G7 standard projectile instead of the G1 standard projectile. The G7 standard is a better match for modern long range bullets, so the...

bergerbullets.com

 

[Greyfox]

I'm mostly a medium sized game hunter using 6.5's at 3000FPS max, I have found my best results from 100 to 1000 yards using Berger140 HVLD and the (discontinued) 142/140 JLK VLD's. At the closer ranges I shoot for the chest/lungs.

 

[Buck Buster]

There seems to be two classes of bullets and if I am incorrect here then I am sure someone will correct me. There are those bullets that will as a rule fragment and blow up at speed but as they slow down 25 or 2400 fps the will penetrate and expand as normal. or those that will expand as normal at speed 31 to 3300 fps and at distance will not do much expanding at 700 plus yards. Would it be impossible for some one like Nosler to take a Partition and add a boat-tail design and an ELDX type heat shield type tip on it . Jack Carter was getting close. Think it would work at up close ranges and also open up at long range?

I have tried the ELDX in different weights and the 178 and 168 grn. Amax bullets shoot obviously better in my 300 Winny shoulder gun and my 308 Norma Magnum bench gun, I am 68 years old and hope I have enough to last me to the end, the 190 grn. Sierra boat tails came in second, but the ELDX's were close to the Sierra's at 300 yard grouping. Before I get all kinds of comments that the ELDX's are superior, stop and think about all guns shooting different, and My shells are reloads, not factory loads ! I was surprised this year, the two deer I shot with the 168's were not blown up at all the first one was at 147 yards and the second was at about 225 yards, both had small exit holes also ? unusual for the 168 Amax bullets, I bought these at Walmart a box of 250, don't know if they are a little different or not, but I like them !

 

[Buck Buster]

P.S. I forgot to say that the 168's I bought before the ones at Wal-Mart blew a pretty good sized hole in a deer until you got out to about 300 yards and farther, that is why I wondered if they were built a little different for Wal-Mart ? The box of 250 was as cheep or cheaper then I bought a box of 100 for at the gun shop .

 

[mmacfive]

Weight is a byproduct of length. A BC of a bullet is more specific to sectional density and form factor. Long bullets tend to have higher BCs with a secant ogive. This is why a 264 cal in 147gr can have a greater BC than a 178gr .308 at a similar speed. The weight alone comes into play with other formulas like momentum in topics related but not limited to terminal performance.

Saying "weight is a byproduct of length" really confuses this discussion for me. Length will be relative to the bullets construction. e.g. a mono bullet will be longer than a lead bullet with the same SDs.

BC = SD/Form factor or mass/square of the bullets diameter/ Form factor. Can't we just leave it at that and call it good?

 

[Capt RB]

Saying "weight is a byproduct of length" really confuses this discussion for me. Length will be relative to the bullets construction. e.g. a mono bullet will be longer than a lead bullet with the same SDs.

BC = SD/Form factor or mass/square of the bullets diameter/ Form factor. Can't we just leave it at that and call it good?

Wouldn't a mono with the same ogive caliber of the same weight have both a better form factor and SD resulting in a higher bc at the same weight?

 

[mmacfive]

Wouldn't a mono with the same ogive caliber of the same weight have both a better form factor and SD resulting in a higher bc at the same weight?

I don't know. I do know that although Barnes LRX are longer they've have nearly the same published BCs as same SD traditional bullets like Nosler, Sierra, etc. Maybe they don't have an optimized form factor?

 

[Vol1975]

There seems to be two classes of bullets and if I am incorrect here then I am sure someone will correct me. There are those bullets that will as a rule fragment and blow up at speed but as they slow down 25 or 2400 fps the will penetrate and expand as normal. or those that will expand as normal at speed 31 to 3300 fps and at distance will not do much expanding at 700 plus yards. Would it be impossible for some one like Nosler to take a Partition and add a boat-tail design and an ELDX type heat shield type tip on it . Jack Carter was getting close. Think it would work at up close ranges and also open up at long range?

accubond long range has good performance at all distance. U can get seconds at Natchez for a good price.
if I'm shooting far I'm flying accubond LR or Berger 215. Both kill. Best I can tell u find one that shoots good groups at distance and go from there. As fair as Berger's at close range I would tell u how fast u are shooting the bullet, how tough of an animal u are shooting and how big a piece of lead you are shooting. I'm not one to use a Berger in a thicket shooting elk but I'll shoot a whitetail. With that being said if u are shooting under 600 yards it's hard to beat a accubond. Don't over think it. And don't look at the shinny new bullet on every shelf.

 

[dfanonymous]

Saying "weight is a byproduct of length" really confuses this discussion for me. Length will be relative to the bullets construction. e.g. a mono bullet will be longer than a lead bullet with the same SDs.

BC = SD/Form factor or mass/square of the bullets diameter/ Form factor. Can't we just leave it at that and call it good?

No. I understand how BC's are formed as well as the difference in monos. You said weight and we're referencing the metallic density differences. As the accurate formula shows, it's not actual weight the brings the BC by itself. The heavier a bullet, the longer it is...this is how they give it the weight, by making it longer, and in general this increases the form factor. If not a .308 will always have a higher bc then a 6.5mm, 100% of the time. This is not always (rarely) the case.

In the case of monos, cutting Edge list the laser .308 @ 180gr a .269 g7. It's also listed at 1.537 in length.

Hornady's 178gr eldx is picture below. I have verified a bc at 1500y in a 20 inch .308 that the true BC in my gun is .271 G7 BC. Length in picture is 1.416 inch. This bullet weight is less, is not as long, and has a higher or pretty much the same BC. The 2 gr heavier laser, makes a .121 difference in length for the extra weight.

All of this for the average shooter is negligible at best. All thing being equal.

 

[mmacfive]

No. I understand how BC's are formed as well as the difference in monos. You said weight and we're referencing the metallic density differences. As the accurate formula shows, it's not actual weight the brings the BC by itself. The heavier a bullet, the longer it is...this is how they give it the weight, by making it longer, and in general this increases the form factor. If not a .308 will always have a higher bc then a 6.5mm, 100% of the time. This is not always (rarely) the case.

In the case of monos, cutting Edge list the laser .308 @ 180gr a .269 g7. It's also listed at 1.537 in length.

Hornady's 178gr eldx is picture below. I have verified a bc at 1500y in a 20 inch .308 that the true BC in my gun is .271 G7 BC. Length in picture is 1.416 inch. This bullet weight is less, is not as long, and has a higher or pretty much the same BC. The 2 gr heavier laser, makes a .121 difference in length for the extra weight.

All of this for the average shooter is negligible at best. All thing being

No. I understand how BC's are formed as well as the difference in monos. You said weight and we're referencing the metallic density differences. As the accurate formula shows, it's not actual weight the brings the BC by itself. The heavier a bullet, the longer it is...this is how they give it the weight, by making it longer, and in general this increases the form factor. If not a .308 will always have a higher bc then a 6.5mm, 100% of the time. This is not always (rarely) the case.

In the case of monos, cutting Edge list the laser .308 @ 180gr a .269 g7. It's also listed at 1.537 in length.

Hornady's 178gr eldx is picture below. I have verified a bc at 1500y in a 20 inch .308 that the true BC in my gun is .271 G7 BC. Length in picture is 1.416 inch. This bullet weight is less, is not as long, and has a higher or pretty much the same BC. The 2 gr heavier laser, makes a .121 difference in length for the extra weight.

All of this for the average shooter is negligible at best. All thing being equal.

let's see here: the longer a bullet gets within a caliber the heavier it gets. Duh. And SD is a byproduct of weight, right? But weight is the byproduct of material, and diameter, etc...

seriously, the formula is BC=SD/FF. If it's how your brain works is to use "weight is the byproduct of length" to help understand BC then more power to you. I understand the formula and will use it.

I understand how BCs are calculated. For me your method adds unnecessary confusion. I hope you've helped others though.

It is more accurate to say the BC increases as the length (therefore the mass) of a given bullet is increased ( if you keep a similar FF).

 

[dfanonymous]

let's see here: the longer a bullet gets within a caliber the heavier it gets. Duh. And SD is a byproduct of weight, right? But weight is the byproduct of material, and diameter, etc...

seriously, the formula is BC=SD/FF. If it's how your brain works is to use "weight is the byproduct of length" to help understand BC then more power to you. I understand the formula and will use it.

I understand how BCs are calculated. For me your method adds unnecessary confusion. I hope you've helped others though.

It is more accurate to say the BC increases as the length (therefore the mass) of a given bullet is increased ( if you keep a similar FF).

SD is the weight in relation to its diameter. Given a caliber, the diameter doesn't change, so....whether you want to say the length gives it weight or the weight gives it length, I don't see being a point worth arguing about. Semantics. However, as we can come to understand, it will come out to the higher SD and usually a higher BC. Again it's not just weight. The disconnect seems to be the weight vs weight proportional to the diameter, so again, weight to diameter is length when talking about bullets. "My method" is not my method...it's just is what it is. The original conversation wasnt to you, it was to grease who was out there making up facts and formulas, and specifically said "the heavier the bullet, the higher the BC is" and "SD is not apart of BC." Both of which are false as you can note in my previous post.

Do you know how to calculate the BC though?

The formula you say you know... is wrong, it's not SD over form factor....I litterally took a picture of Bryan litz's book and linked to Berger website with the formula. All you needed to do is copy and paste it if you wanted to just argue and you didn't even get that right. I don't know how else to spoon feed it.