230 hybrid, berger reduced its bc?

[gilmillan1]

Does anyone know why berger reduced the bc of the hybrid 230s? It used to be .74 and now it is .71

 

[Berger.Fan222]

http://www.bergerbullets.com/update-of-berger-bullets-performance-data/

This link explains some recent changes in Berger's BCs.

 

[JasonT]

Just to clear it up, the bullets haven't changed AFAIK - However, further testing just showed slightly different flight characteristics than originally calculated.

For this bullet, shouldn't we all be using the G7 BC anyway? I don't believe that has changed much at all (from .38 to .368), or about 3.2%.

I shoot this bullet from a long-throated .308 Winchester, so I benefit a lot from the high BC and weight. My calculations with a MV of 2500fps show the difference in drop at only 0.15 mils (~.5 MOA) at 1000 yards. And with a MV of 2500fps and 10mph crosswind, the difference in wind drift at 1000 yards is only 0.07 mil (~.25moa).

These kinds of changes are so small, that I don't think I'd notice unless I were really, really concentrating and I guessed the wind along the whole flight path exactly.

Jason T. Fridlund
Advanced Kinetics

 

[barefooter56]

Does anyone know why berger reduced the bc of the hybrid 230s? It used to be .74 and now it is .71

gilmillian1,
Jason T nailed it. No changes to bullet design. What happened was that through advancements in be able to , for lack of a better word, "track" the bullets which gave us better information. We always want you guys to have the latest data so you can make good decisions.
Hope this helps!

 

[barefooter56]

Just to clear it up, the bullets haven't changed AFAIK - However, further testing just showed slightly different flight characteristics than originally calculated.

For this bullet, shouldn't we all be using the G7 BC anyway? I don't believe that has changed much at all (from .38 to .368), or about 3.2%.

I shoot this bullet from a long-throated .308 Winchester, so I benefit a lot from the high BC and weight. My calculations with a MV of 2500fps show the difference in drop at only 0.15 mils (~.5 MOA) at 1000 yards. And with a MV of 2500fps and 10mph crosswind, the difference in wind drift at 1000 yards is only 0.07 mil (~.25moa).

These kinds of changes are so small, that I don't think I'd notice unless I were really, really concentrating and I guessed the wind along the whole flight path exactly.

Jason T. Fridlund
Advanced Kinetics

Jason T,
YES! always use the G7 BC! Its formulated around boat tail bullets and is good for all velocities from muzzle to end of flight. The G1 is based on flat base bullets and is only correct for certain velocities in the bullets flight down range. Check the SIERRA manual for how they do their G1 BC s for their bullets. They list the different ranges/velocities and the G1 BC values at those points.

 

[gilmillan1]

I had planned on shooting a 300 wsm because the bc was significantly higer than the 180 hybrids. 180 hybrid was .67 and the 230 hybrid was .74. if you tip these bullets you can add a 4-5% increase at 1000 yards. Now the 180s are .68 and the 230s are .71. i now question whether it would be a good idea to build a 300 wsm based on these numbers.

 

[JPeelen]

We have to accept the fact that G1 simply does not fit the drag curve shape of modern slender bullets. Any G1 BC can only be a compromise to make the best of a bad situation. Do not worry about .74 versus .71, because on average G1 is much farther off the real drag curve than this small difference.

But I have to rain on Phil's parade insofar as boattails do not have much to do with this. I have analyzed data for a number of FMJ bullets and found that even bullets without boattail in most cases fit G7 better than G8 (which is the drag model for straight base bullets).

For any modern bullet with a slender ogive, boattail or not, G7 is a drag model that may not be perfect but does the job as a standard very well.

 

[JasonT]

Thanks Phil! Glad to see Berger supporting their products on here!

 

[gilmillan1]

phil, what do you estimate would be the difference in wind drift between the 180 hybrid (7mm) and the 230 (30) in a 10 mph cross wind? Both bullets traveling at 2850.

 

[gilmillan1]

by the way, thank you for such an informative answer

 

[Berger.Fan222]

Building a heavy .30 cal for F-Class doesn't make sense given the recoil involved and the high BC 7mm bullets. But these heavy .308 bullets do make sense if you already own a heavy .30 cal and want to take it for a spin in F-Class. Recoil is not too bad if you get the rifle up to the full 22 lbs. We have a heavy .300 Win Mag that my son is enamored with. I shoot it with a brake, but we add a few pounds of weight and unscrew the brake and it makes a serviceable F-Class rifle. If he ever grows out of this one, I'll likely recommend a .284 Win for the next one.

 

[barefooter56]

phil, what do you estimate would be the difference in wind drift between the 180 hybrid (7mm) and the 230 (30) in a 10 mph cross wind? Both bullets traveling at 2850.

gilmillan1,
Run your data on our BALLISTIC CALCULATOR found on our website main page under the BALLISTICS tab on these two Bullets to see whats up. You can also find our TWIST RATE CALCULATOR there also. There are some great tools you can use for free on our website to help you answer many of your questions. If they dont fit your issue. Call us on the Berger Tech-line Monday thru Friday from 8 am to 4:30 pm EASTERN time. 714-441-7202 or post on the FORUM here if you wish.