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Old September 18, 2012, 09:29 PM   #1
ky hunter
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Point Blank

Was shooting my 300 win mag 165 gr pill through my millennium 2 chronograph reading 3141fps bullet has a BC I think of 0.387. MY line of sight is 1 1/2 above bore what would be my two point blank zeros? I once read sight it to zero 30 yards and it will rise from there and on the drop side it's zero @330 yards. Is this statement wright? Can you help me find my two point blank ranges?
It's much easer to sight in at 30 yards than 300 +/- it's a lot less walking if you know what I mean. And what is max rise between the two? Thanks from ky hunter.
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Old September 18, 2012, 10:33 PM   #2
Jimro
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Ran those numbers through JBM ballistics calculator, zero at 315 yards, and you don't go above +5 or below -5 out to 360 yards.

Or more easily, zero 3.7 inches high at 100 yards and just hold center aim out to 3 and a half football fields.

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Old September 19, 2012, 06:23 AM   #3
ky hunter
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Thanks Jimro but do you know what the zero is under the 100 yrd mark is on the rise?
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Old September 19, 2012, 12:07 PM   #4
Jimro
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3.7 inches high at 100 yards gives you the 360 yard Max Point Blank Range zero for +/- 5 inches.

Sorry if I didn't make that clearer. The actual "zero" for that MPBR is 315 yards, which is an odd range to zero at.

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Old September 19, 2012, 01:25 PM   #5
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A BC of .387 seems impossibly bad for a 165 gr bullet. I'm shooting 165 gr Hornady interlocks with a BC of .435, SST's are .447 and Nosler Accubonds are .475

I'd check to be certain of the BC. It will make a huge difference at longer range in both trajectory and energy. If you are really shooting a 165 with a BC of only .387 I'd be trying different bullets.
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Old September 19, 2012, 01:33 PM   #6
Sweet Shooter
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iSnipe it...

Ky, is not asking for MRT @100 yards. He is asking for PBR#1 when MPBR is pushed out to 330 yards.

Ky, this will help you find that first convergence/PBR when zeroed at any range you ask. This little app is worth every penny and the range-finding capabilities and environmental calculations actually work quite well.

I can't get to my phone right now else I'd just dial it for you. There are tonns of factory cartridge offerings and you can also save your user hand-loads too... you tell it what you know and it tells you what will happen.

-SS-

Last edited by Sweet Shooter; September 20, 2012 at 01:10 AM.
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Old September 19, 2012, 01:38 PM   #7
Brian Pfleuger
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+5 inches is a lot more than I'd want to be at for my basic zero.

I don't like being above 3 inches, at most.

Typically, you've got time to adjust the scope for long shots but when you're 5 inches high at what are much more common ranges, you've got to stop and figure out where your bullet might be at that range. Anything smaller than elk (and it's pushing it with elk) 5 inches high is plenty enough to make a good shot into a bad one.

I almost always sight in somewhere around 1 1/2 (less for super flat rounds, more for slower ones) high at 100 yards.

With the specifics of your load, I'd personally go about 2 inches high at 100, that puts you 2 1/2 high at 140, which would be a 240 yard zero and 2 1/2 low at 280.
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Old September 19, 2012, 02:23 PM   #8
Jimro
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Running the numbers for +/- 3 inches gives...

300 yards max point blank range, zero 2.5 inches high at 100 yards.

Although if I knew the exact bullet used that might change a little.

On another note, whether or not it is +/- 5 or 3 inches really depends on the size of animal you intend to shoot. Florida Deer are definitely smaller than Roosevelt Elk.

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Old September 19, 2012, 03:10 PM   #9
Sweet Shooter
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Quote:
@ky hunter
Was shooting my 300 win mag 165 gr pill through my millennium 2 chronograph reading 3141fps bullet has a BC I think of 0.387. MY line of sight is 1 1/2 above bore what would be my two point blank zeros? I once read sight it to zero 30 yards and it will rise from there and on the drop side it's zero @330 yards. Is this statement wright? Can you help me find my two point blank ranges?
It's much easer to sight in at 30 yards than 300 +/- it's a lot less walking if you know what I mean. And what is max rise between the two? Thanks from ky hunter.
Q1. Assuming 165 gr BC of 409-G1 your first actual "0" on the path is at 27 yards.
Q2. I'd go with a Maximum Point Blank Range of 320 yards, putting you on at 30 yards and again at 270 yards, with a mid range trajectory of +3.2 at 150 yards and -3.5 at 320 yards.

-SS-
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Old September 19, 2012, 03:47 PM   #10
ky hunter
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Thanks Sweet Shooter just the answer I was looking for the bullet is 165 rem CL PSP like I said not for sure on the BC number.Your BC number is probably closer.
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Old September 19, 2012, 04:07 PM   #11
ky hunter
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Sweet Shooter check in to that app it sounds like it would be fun to play with.
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