Can someone explain this to me?

The Oregonian

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Jul 20, 2012
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Missoula, Montana
I don't understand why the ballistics data Shooter is giving me makes sense. I am comparing two guns....a 28N with a 195 Berger (BC of .755) with a MV of 3000, and a 280AI with a 168 VLD (BC of .618) with a MV of 3010. All other data for the ballistics chart is the same...both an 8 twist, and all environmentals are identical.

The 28N is essentially the same speed as the 280AI but much higher BC. The 28N starts out with much higher energy, a little more than 500 ft lbs, and yet with a higher BC bullet with essentially the same MV, carries 200-ish ft lbs less energy at 70l0 yds and 450-ish less energy at 1200. I bring these up not to debate whether they are fast or slow, but to give the inputs into the charts.

it seems to me that either I have done something wrong, which I wont rule out but I have been using the app successfully for years and feel I know it decently well), the app is messed up, or I don't understand the science (lay person but think I understandnthe key points) like I thought I did.

To proactively answer any other questions to keep this on track, both rifles are from MOA, and the 28N is with Retumbo while the 280AI is with N560. The 28 has a 26" barrel and the 280 has a 25". MV is based off Labradar.

Put aside the specifics of this example...all else equal, shouldn't a much higher BC bullet, with the same MV and much more energy at the muzzle, have that energy advantage grow over distance and have less drop? Isn't that just science? What could be causing this (other than app or user error).

Thx

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First I'll say, that's on the very low end for the 28 Nosler with 180s, and at the very top end for the .280 AI with 168s. You say 180 VLDs for the 28 Nosler, but your chart says 195gr?
 
I understand bullet design and general bc....
But to achieve actual bc for a bullet thru a barrel...isnt the BC ALWAYS subject to velocity.....
 
Check both of your inputs on weight of the bullet. I bet one of them is wrong. I get 1006 ft lbs of energy with the 168 at 1200 yards. And 1482 ft lbs of energy with the 195 at 1200.

Check all data you put in. Something is wrong haha.
 
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Thanks...this is on my iPad which I only use to look at info in my living room so I never shoot a solution based on this. The one on my iPhone is what i use in the field if needed. The iPhone app and my G7 are correct.
 
I don't understand why the ballistics data Shooter is giving me makes sense. I am comparing two guns....a 28N with a 195 Berger (BC of .755) with a MV of 3000, and a 280AI with a 168 VLD (BC of .618) with a MV of 3010. All other data for the ballistics chart is the same...both an 8 twist, and all environmentals are identical.

The 28N is essentially the same speed as the 280AI but much higher BC. The 28N starts out with much higher energy, a little more than 500 ft lbs, and yet with a higher BC bullet with essentially the same MV, carries 200-ish ft lbs less energy at 70l0 yds and 450-ish less energy at 1200. I bring these up not to debate whether they are fast or slow, but to give the inputs into the charts.

it seems to me that either I have done something wrong, which I wont rule out but I have been using the app successfully for years and feel I know it decently well), the app is messed up, or I don't understand the science (lay person but think I understandnthe key points) like I thought I did.

To proactively answer any other questions to keep this on track, both rifles are from MOA, and the 28N is with Retumbo while the 280AI is with N560. The 28 has a 26" barrel and the 280 has a 25". MV is based off Labradar.

Put aside the specifics of this example...all else equal, shouldn't a much higher BC bullet, with the same MV and much more energy at the muzzle, have that energy advantage grow over distance and have less drop? Isn't that just science? What could be causing this (other than app or user error).

Thx

View attachment 194382


View attachment 194383
Something is not right with your input data. Your 280 shows 5.5 inches wind drift @ 500 in 10 mph wind. Your 28n shows 9.5 inches drift in the same 10mph wind @ 500. There is no way the 280ai is bucking the wind that much. Check what B.C value you put in for the 280ai.
 
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