# Ballistics Calculator Question

Discussion in 'Long Range Hunting & Shooting' started by pdkillr, Feb 6, 2013.

1. ### pdkillrMember

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15
Joined:
Jul 14, 2008
Okay going to try and explain this where you guys can give me an answer. I use the Big Game calculator. I enter in my info and it tells me the # of clicks up out to 600 yds. I shot yesterday at 2/3/400 yds. Zeroed at 200. according to the calculator it said at 300 -6.7 low and 17 clicks, actual at 300 was about -5.5 in low and at 400 calc says -20.5 and 39 clicks actual was about -16.5 in low. Okay so my question is can I just change velocity in calulator to get me where I need to be according to my shooting on the target. IN other words get my actual drops? And if I can change it that way should I be good out to 6 or 700 hundred yds or do I need to shoot at those ranges too? Thanks

2. ### HuntFartherWell-Known Member

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611
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Dec 13, 2012
Yes you can change your muzzle velocity and b.c. if need be. The first drop chart is mainly a refrence start point. Usually done by using a bullets manufactured b.c, and using muzzle velocity gathered over a chronograph. But make sure you are not ignoring the parth to input altitude and pressure. If you have no way to read pressure atleast use the part of the program where it gives you a generic output based off of elevation to get you close.

3. ### BrentMWell-Known Member

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1,550
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Jan 10, 2013
In the video section by gunwerks there is tutorial on this subject. Pretty cool. You are on the right path, given you did as suggested and input the right elevation, temp, and pressure. Without those the data you are comparing is meaningless.

Temp
Elevation
Pressure
Shot angle

These have the most affect on drop from what I have experienced. Humidity does too but at far less rate for shorter distances, ie under 1000.

Let's say you did infact have that data input correctly....then adjusting velocity is the way I would have gone. I actually didn't think about BC all that much as I shoot bergers and thought there data was highly accurate. Now that it has been mentioned I would like to play with that info on my program too.

4. ### elkaholicWell-Known Member

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5,347
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Dec 4, 2008
Also, have you actually checked the click values on your scope? They are rarely spot on and can be off considerably. Usually it is more of a problem at longer ranges than 600 yards though.......Rich