Relationship between Ballistic Coefficient and Sectional Density

[YellowHammer]

Will someone please try and tell me something I didn't know about this topic.
I understand how B.C. plugs into my ballistics. But how this came about was I am shooting two bullets that are the same weight, same shape, same size, and same type. They are the Traditions Smackdown SST & the CARNIVORE. They are both 250 gn polymer tipped bullets that are lead electroplated with copper. But the B.C. of the SST is .210, and the B.C. 9f the CARNIVORE is .262. They look identical to the eye. So after thinking awhile I thought the only way I s if the sectional density is different. Than that would allow for a higher B.C.????? But now I don't really know how or of sectional density would apply here. Hard for me to understand how twonalmost identical bullets can be sondiff in the B .C.


Thanks for your time,

T. Brady

 

[HC]

BC was probably measured at different velocity. Bullet manufacturers will cheat a little to say their bullets are better, in order to sell their product.

 

[Okie Hog]

The Traditions SST bullet jacket is not electroplated. It's a Hornady SST.

"The Traditions Smackdown™ SST Bullets consist of an interlocked copper jacket with a solid lead core for controlled bullet expansion. The bullet's Super Shocked Tip (SST) was designed specifically by Hornady® for extreme performance at all muzzleloading velocities. Voted "Best-of-the-Best" for new, innovative ammunition products by Field and Stream in 2010, the Smackdowns come in a .50 caliber sabot with a .45 caliber bullet. The SST features Traditions' proprietary yellow spire point polymer tip that supports bullet expansion upon impact."

Traditions™ Smackdown® SST Bullets 250 & 300 Grain | 15 Pack | Muzzle-Loaders.com

 

[GM54-120]

Sectional density is a mathematical equation. Its constant. All 250gr 45cal bullets will have the same SD. Roughly .170-.175

BC is not constant even velocity changes the BC. It is also one of the most inflated numbers thrown out there by some companies. The Carnivore is made by Berry bullets for Traditions. They made them for years before Traditions picked them up. A .262 for a 45cal 250gr sounds pretty inflated in my book.

Berry claims their Blue Diamond 250gr is .220 BC. Im curious how Traditions got such a huge BC boost from the same bullet.
https://www.berrysmfg.com/product/bp-50-250gr-muzzle-ldr
https://www.traditionsfirearms.com/product/smackdown-carnivore-bullets-250-grain-.50-caliber

 

[52Bore]

If one is longer - it will have a better BC.
SD same, if same weight & diameter.

Also, there is BS in many published BC’s with respect to ML projectiles.

 

[ENCORE50A]

...................... BC is not constant even velocity changes the BC. It is also one of the most inflated numbers thrown out there by some companies.......

Excellent! Velocity makes a tremendous difference. I've shot a lot of different bullets in the last 5-6yrs and every one of them require an adjustment to the BC using JBM. Actual range time and distances will cause you to adjust every BC.
Now I will say that there are bullets that are DARN CLOSE to the advertised BC but, those bullets are also very expensive.
For 95% of most shooters who never shoot long range, in many cases BC won't matter.

 

[snapbang]

BC is not constant even velocity changes the BC. It is also one of the most inflated numbers thrown out there by some companies.

I ran into "optimistic" numbers when I spent the last 35 years reloading for a 243 Winchester. For velocity and BC the manufacturers are always looking to make their product seem a little bit better. I look forward to shooting the various black powders, substitutes, and conicals over a chrony. I assume they are "optimistic" numbers as well. Some more so than others.

 

[YellowHammer]

Sectional density is a mathematical equation. Its constant. All 250gr 45cal bullets will have the same SD. Roughly .170-.175

BC is not constant even velocity changes the BC. It is also one of the most inflated numbers thrown out there by some companies. The Carnivore is made by Berry bullets for Traditions. They made them for years before Traditions picked them up. A .262 for a 45cal 250gr sounds pretty inflated in my book.

Berry claims their Blue Diamond 250gr is .220 BC. Im curious how Traditions got such a huge BC boost from the same bullet.
https://www.berrysmfg.com/product/bp-50-250gr-muzzle-ldr
https://www.traditionsfirearms.com/product/smackdown-carnivore-bullets-250-grain-.50-caliber

That's what I'm wondering, I was aware they were the blue diamonds. The reason it matters to me so much is bc according to my Nikon spot on app, just the B.C. going from .210(sst) (and the ssts I have are electroplated I can tell the difference electroplate is shinier, they say they are interlocked on the package as well but that's another story)and .262 Carnivore it will potentially change my zero from 100 yards to 130 yards. Bc qith the higher B.C. I prefer the cleaner numbers I get from the 130 yard zero. I haven't shot my bdc yet ti verify but I have cross deference the spot on numbers against every available source and they are always ballpark or dead on. I think nikon took the median of every available number on thier app I've never seen it wrong!!!

 

[GM54-120]

SST/FTX/Shockwaves are not electroplated. They are all cup and core jacketed bullets made by Hornady.