ballistic coefficient questions . 6.5 mm bullets

[Outlaw6.0]

Originally Posted by MontanaRifleman

With the 130's showing an estimated .56 BC, it's doubtful the 140's will increase to more than .6. In fact, a .04 jump for 10gr increase in mass is probably optimistic.

Not necessarily, Berger is a prime example. The 130 is .555-ish & the 140 boasts about .612. I was figuring the same ~60 point jump on the CEB to .620 ish.


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[bigngreen]

Originally Posted by Cold Trigger Finger

Which 140 Berger? Ill be starting a 140 at around 2700 fps . I see they have a heavy jacket target bullet. . Any idea if its slower opening than the hunting VLD in 6.5 ?

The 140 Berger hunting bullet would be the best place to start, the target and hybrid have a thicker jacket. I do use the Target bullets sometimes if I want a little slower opening of the jacket but the 6.5 140's hunting don't open fast anyway from what I've seen in all the game we've taken with them and we run them faster than you will, even close the hunting vld has worked good for us, we aren't picky if they get stupid they die close

[MontanaRifleman]

I hope you're right... we'll probably be finding out

[MontanaRifleman]

Would closing or blocking the hollow point be a bad thing for fur hunting?

[Cold Trigger Finger]

How about Lapua bullets. Are the b c s they quote accurate for their bullets? ? Are the Secnar's equal to Sierra, Hornady and Berger for accuracy?

[Beng]

If the 140gr's form factor is the same as the 130gr's and assuming the .56 bc of the 130gr is correct, then the 140gr bullet would have a bc of .603.
The 130gr CEB's form factor is similar to the Berger 140gr VLD's form factor, so, if you have one of the latter at hand, just compare the 130gr CEB's ogive and boattail to the Berger's.
I'd wager the ogive is shorter than the Berger's ogive.

[Edd]

The difference from .600 to .620 is 2 inches at 800 yards at sea level.