ballistic coefficient questions . 6.5 mm bullets

[Cold Trigger Finger]

So since getting my 6.5 Creedmoor I've been studying the bullets that hopefully will work best for my purposes.
When checking the BC of many bullets I found what appears to be a misprint. But since I'm not to good at math I am hoping someone who understands this could explain it. .the 2 bullets in question are the 140 gr Hornady SST and the 130 gr Sirrocco II.
the SST has a BC of 520 and the Swift's BC is 571 .
The SST is longer than the Swift and appears to be more streamlined. What is the cause of the. 05 difference.

Thanks in abvance.

 

[Shooter264]

Swift has grossly inflated their BC's for years. You will find if you shot them at yardage they are not even close to as advertised.

 

[Cold Trigger Finger]

OK, so would the real world BC of the Sirrocco bullet be similar to the 130 gr AccuBond. ??

 

[Shooter264]

I can't answer that as I have no experience w the accubond. I'm not a Nosler fan at all. Sorry I'm no help on this.

 

[Cold Trigger Finger]

No, I really appreciate it. I got a box of the Swifts because they had such a high BC listed. When camparing them side by side with the 140 SST they werent anything to write home about. .

I see Nosler is making the 140 gr AB

 

[bigngreen]

You really owe it to yourself to try the 140 Berger in a 6.5, it's BC is nuts on and the performance is hard to beat, my dad's been through a lot of bullets in his 6.5 Sherman and just keeps coming back around to the 140 Berger.

 

[Shooter264]

You really owe it to yourself to try the 140 Berger in a 6.5, it's BC is nuts on and the performance is hard to beat, my dad's been through a lot of bullets in his 6.5 Sherman and just keeps coming back around to the 140 Berger.

+1 on the VLD.

 

[MontanaRifleman]

Most manufacturers do overstate their bullet's BC's. Bryan Litz has tested many of the popular bullets and printed the results in his books, Applied Ballists. In the first volume he lists the 130 Scirocco with a G1 BC of .491 averaged from 3000 to 1500 fps. He does not list the 140 SST, but rates the 129 gr SST and 140 A-Max at .483 and .584 respectively. He rates the 140 AB @ .487

 

[Cold Trigger Finger]

OK. Well the Hornady book lists the same BC figures for the 129 SST and the 140 A MAX . So they look reliable. I don't like bullets that are real fragile as I will get a lot more close range shots than even 500 yard ones.

 

[bigngreen]

OK. Well the Hornady book lists the same BC figures for the 129 SST and the 140 A MAX . So they look reliable. I don't like bullets that are real fragile as I will get a lot more close range shots than even 500 yard ones.

The SST is one of the more frangible bullets you could be shooting, far more than a 140 Berger.

 

[benchracer]

If you decide to go with bullets in the 130g weight range, the Hornady 6.5 bullets in that weight range are a good choice. The 129g SST's are inexpensive to shoot and can be reserved for use at longer ranges where their frangibility is an asset because of lower impact velocities. Hornady also offers the 129g Interbond, which would give you the option to use the tougher bullet at shorter range.

The bc for the two bullets is identical. Given careful load development, I would expect the two bullets to have similar POI's. It could be a useful pairing. I just wish Hornady would do something similar in the 140g range to offer a tougher bullet to pair with the 140g AMAX.

In my faster 6.5's, I am pairing the AMAX with Partitions. In my Swedes, I am using Bergers. I don't think they are fast enough to really need a tougher bullet.

 

[Cold Trigger Finger]

I thot the SST was basically a slicked up Interlock.
I wish Barnes would make a 140 gr TTSX. And that ATF would let them make their Banded Solids again.

Ive never shot a Berger bullet. Just never liked their description of the bullet shedding weight. . .
It would be nice if Hornady made a 140 gr Interbond

I'll research the Bergers . Thanks again. !

 

[Cold Trigger Finger]

Most manufacturers do overstate their bullet's BC's. Bryan Litz has tested many of the popular bullets and printed the results in his books, Applied Ballists. In the first volume he lists the 130 Scirocco with a G1 BC of .491 averaged from 3000 to 1500 fps. He does not list the 140 SST, but rates the 129 gr SST and 140 A-Max at .483 and .584 respectively. He rates the 140 AB @ .487

Thanks. Are there any sponsors here that sell this book that you know of. Or do you know where I could get a copy? ?

 

[Mikecr]

AB for Long Range Shooting