# Buck down. CVA OPTIMA 200yards at the range and field



## utahhunter678 (Nov 3, 2012)




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## muddydogs (Oct 7, 2007)

How far to the left was the rifle off between 100 and 200 yards? Hard to tell from looking at the target paper but it would be enough to concern me that when shooting at 100 yards the bullet is now impacting to the right of where you want it. Wonder if you meant to put the shot through the deers shoulder or if it was closer then 200 yards and the round missed the behind the shoulder shot and punched the shoulder?

You sure talked up how well the muzzy grouped and it all looked good until the 200 yard shots. I would have expected the left and right to be the same as 100 yards with just a little height adjustment needed.


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## utahhunter678 (Nov 3, 2012)

Muddydog
Thanks for the comment. When I went out to 200 yards I was about 5 inches left. I am very glad I went to 200 to shoot because I also did not expect the round to hit that far off.

My shot at the buck was about 90yrds when I ranged back to where I shot from.
I got down on one knee and held the crosshair on the brisket of the buck. knowing I would hit high. I wasnt sure of the range but i knew I was about 100yrds I was not intentionally trying to hit the shoulder. It happened so fast that I was really just trying to hit vitals. I am happy with the shot because it put the buck down fast and I did not have to do any tracking.


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## USMARINEhuntinfool (Sep 15, 2007)

Awesome!


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## DallanC (Jan 13, 2009)

utahhunter678 said:


> Muddydog
> Thanks for the comment. When I went out to 200 yards I was about 5 inches left. I am very glad I went to 200 to shoot because I also did not expect the round to hit that far off.


Its called Bullet Precession and has been known for over 100 years. Unfortunately +99% of modern hunters dont have a clue it exists or its effect. They think a 1MOA group at shoots 1" @100, 2" @200 etc etc. That is a false assumption.

Did you know a in alot of cases a rifles MOA isnt fixed? The MOA can and will change over distance as precession increases / decreases due to spin, bullet design etc etc.

I've seen guns shoot 2.5" MOA @100 yards and settle in to sub MOA at 200.










All of this knowledge is becoming lost I fear... /sigh

-DallanC


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## DallanC (Jan 13, 2009)

This will blow your minds further... if you have a slightly upset bullet spinning with precession, its path as viewed along the axis of travel resembles the "nutation" path shown above, it will actually corkscrew around the axis of travel. So, at 50 yards it might have only traveled 1/4 of a rotation, yet at 100 it might be 1/2 of a rotation etc etc. The point of impact on paper will change according to distance and how it rotates around the line of sight axis the bullet travels. This would lead one to believe they have a very crappy grouping rifle when it actually might be very accurate, just the groups follow nutation along the axis. 

Something (usually the crown) is upsetting the bullet as it leaves the barrel causing the bullet to be slightly upset and not on the same axis as the LOS.

External ballistics are fascinating at times. There is no way to model this however in a computer ballistics program, as its usually very unique to the rifle itself.


-DallanC


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## utahhunter678 (Nov 3, 2012)

Great comments. Thx a bunch.


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## ridgetop (Sep 13, 2007)

Congrats on your buck.


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## 1trhall (Oct 18, 2017)

DallanC said:


> Its called Bullet Precession and has been known for over 100 years. Unfortunately +99% of modern hunters dont have a clue it exists or its effect. They think a 1MOA group at shoots 1" @100, 2" @200 etc etc. That is a false assumption.
> 
> Did you know a in alot of cases a rifles MOA isnt fixed? The MOA can and will change over distance as precession increases / decreases due to spin, bullet design etc etc.
> 
> ...


Right on Dallen. It's why most long range shooters do all their load development testing at 200 yards rather than 100.


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