Who uses G1 or G7 Pros cons

Pappasniper

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Im getting more familiar with my new Ballistic calculator. I started with the Shooters App. and now have the Ballistic AE app. As always they offer the G1 or G7 settings. Which do you use and why?

Pro's Cons if you will.

Any help appreciated.

PB
 

SD carpenter

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Don't quote me... But the g7 is the newer unit of measurement, and also if they kept at g1 the numbers would be pretty high
 

ZY100

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G1 drag model is older and based on a flat based bullet profile. G7 is a newer model and based off a sleeker, boat tailed bullet most of us shoot.

In theory the G7 model is closer to what we use, but the G1 numbers are (usually) based on actual performance (regardless of bullet shape) and end up working well too.

Not smart enough in it to quantify how much “better” one is for our solvers.

FWIW....I use G7. But a lot of people still use G1 with good results. PRS/NRL probably not as critical as ELR....

ZY
 
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ShtrRdy

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The Ballistic Coefficient is made from a "drag curve" which relates bullet drag to velocity. The G1 BC is based on a short-fat bullet with a flat base and broad tip. The G7 BC is based on a slender bullet with boat tail and a pointy tip. To get the closest ballistic trajectory out of a ballistic app/program it's better to use the G7 BC.

You can have some decent results using the G1 BC but the drag curve doesn't match very well over a wide range of velocity. If you've ever looked at Sierra bullet BC being specified for different velocity ranges - this is the reason why.
 

Pappasniper

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Thanks fellas, G7 it is. Im running SMK in 308 and ELD M in 6.5 and 300WM, so yeas G7. Or at least along those lines.

PB