Ballistics calculator ....?

tfox

Ok guys was messing around on a ballistic calculator trying to come up with my perfect load. What was confusing me was the different results I was getting depending on what zero range I put in ...?

For example if I put in 100 yds was getting a drop of 4.5 at 200 hundred - 4.5 inches of difference.

If i put a zero of 200 yds it is 1.4 inches high at 100 - a difference of 1.4 inches ...?

I'm sure there is a logical explanation for this, so please educate me :rolleyes:

I'm sure my boss could give me a long and lengthy explanation tomorrow but that could last all day and I'm one of those guys that likes to get some work done Helps come payday

sfakiaman

You don't say what calibre you're using but the bullet drop over 200yds will be the same anyway. If you're using a scope hight of 1.5ins the bullet has to climb that much to reach line of sight, this means you are zeroed at two distances, the first where the bullet passes through the line of sight and is still climbing and again where it falls through the line of sight. If you're zeroed at 200yds then the bullet will still be climbing at 100yds but if you're zeroed at 100yds the bullet is falling below the line of sight after that having passed upwards through the line of sight at around 60yds (for a .308).

Anyway thats my story and I'm sticking to it

tfox

Of course what I wasnt taking into consideration was that 4.5 inches at 200 equates to 2.25 inches at 100 which does help to explain it more. If I'd looked at the calculator properly I would've seen the little box with drop in MOA in it aswell

Tackleberrywho

tfox wrote: »

Of course what I wasnt taking into consideration was that 4.5 inches at 200 equates to 2.25 inches at 100 which does help to explain it more. If I'd looked at the calculator properly I would've seen the little box with drop in MOA in it aswell

Is it a computer based or hand held jobbie?

i often considered getting a hand held one.

virminhunter

sfakiaman wrote: »

You don't say what calibre you're using but the bullet drop over 200yds will be the same anyway. If you're using a scope hight of 1.5ins the bullet has to climb that much to reach line of sight, this means you are zeroed at two distances, the first where the bullet passes through the line of sight and is still climbing and again where it falls through the line of sight. If you're zeroed at 200yds then the bullet will still be climbing at 100yds but if you're zeroed at 100yds the bullet is falling below the line of sight after that having passed upwards through the line of sight at around 60yds (for a .308).

Anyway thats my story and I'm sticking to it

this is the same view I have on a bullets trajectory, but after reading a few posts over the past while from different people on different forums their saying that the minute a bullet leaves the barrel the bullet is dropping

In response to the origional question, 1moa at 100yards is 1.04 inches, 1moa at 200yards is 2.08 inches, and so on, if I'm zreo'd at a hundred yards and the bullet drop out to 200yards is 2.8inches then to zero my rifle at 200yard I click up 1.4 moa because 1.4 moa(1.4inches) at 100yards is 2.8moa(2.8 inches) at 200yards, hope this helps...:)

Tackleberrywho

Don't fcuk with the Chuck

http://www.chuckhawks.com/rifle_trajectory_table.htm

2 MOA is 2"@100 4"@200 6" @300 and 8"@400

My scope has deviations 2MOa apart "nightforce"

If I am zero @ 200 yards and I want to hit a bunny @ 300 I use the next line down on my scope and that has compensate the .223 drop @300

It's worked to date for me on Bunnies 300+yards
http://nightforceoptics.com/nightforcescopes/RETICLES_OVERVIEW/RETICLES_DETAIL/NP-R2-32x.pdf

virminhunter

tfox wrote: »

Of course what I wasnt taking into consideration was that 4.5 inches at 200 equates to 2.25 inches at 100 which does help to explain it more. If I'd looked at the calculator properly I would've seen the little box with drop in MOA in it aswell

sorry tfox I didnt see this post where you figured it out, my bad...:rolleyes:

Cass

Tackleberrywho wrote: »

If I am zero @ 200 yards and I want to hit a bunny @ 300 I use the next line down on my scope and that has compensate the .223 drop @300

Only if you use the preset ranging magnification setting on your scope. Any other magnification setting and the MOA marks on your crosshairs will not give you true measurements.

sfakiaman

virminhunter wrote: »

this is the same view I have on a bullets trajectory, but after reading a few posts over the past while from different people on different forums their saying that the minute a bullet leaves the barrel the bullet is dropping

In relation to a straight line from the barrel then the bullet is dropping, but the barrel is pointing upwards in relation to the line of sight therefore the bullet is rising in relation to the line of sight, untill it reaches its apogee that is.

Wreak your head that stuff would

tfox

Tackleberrywho wrote: »

Is it a computer based or hand held jobbie?

i often considered getting a hand held one.

It is on the Hornady website
http://www.hornady.com/ballistics-resource/ballistics-calculator

My boss gave me a long and lengthy explanation this morning which resulted in a practical demo to finish !! When he explained it all it made perfect sense They guys been shooting match rifle since he was a schoolboy in England, perxonally I think he learnt it all in the trenches