# eliminator 3 users

Discussion in 'Long Range Scopes and Other Optics' started by ZSteinle, Mar 12, 2013.

1. ### ZSteinleWell-Known Member

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920
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Jan 30, 2008
Quick question for anyone that might have the answer. With the instructions to determine drop the scope uses your drop at 750 yards and a bc. Well it tells you to adjust your bc x amount for going upin elevation or down in elevation above sea level. Now my question is can I just put my information into jbm ballistics to get my 750 yard drop in inches and keep my bullets b.c. the same. I feel like this would be much easier. Make a chart for drops at different elevation and say I go up to 10, 000 feet and mu 750 yard drop is 145 inches with a bc of .550. I couldnt see how it could confuse the computer any? Any input would be great.

2. ### LouBoydWell-Known Member

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770
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Oct 15, 2007
If he scope's computer program doesn't have an input variable for altitude then changing the effective bullet BC is the appropriate correction of make to correct for the reuded drop when shooting at a higher altitude. Don't change the muzzle velocity to try to get a fit. You can use the JBM program to determine the effective BC to use to make the drop come out right. The same (higher) BC will also correctly predict wind deflection for shooting at the higher altitude.

3. ### ZSteinleWell-Known Member

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920
Joined:
Jan 30, 2008

Thanks for your reply. The scope does not have an input for muzzle velocity. You enter your bullets drop at 750 yards and your bc in order for it to determine your drops. I am thinking of keeping the bc the same (0.53) and adjust my 750 yard drop numbers according to altitude. But after reading the directions a few more times it seems to be clear now.

4. ### LouBoydWell-Known Member

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770
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Oct 15, 2007

Two bullets with different mzzle velocities and different BC can have the same drop at 750 yards but have different drops at other distances. All that having the same drop means is that both bullets reached 750 yards in the same amount of time. The bullet with the faster muzzle velocity will have less drop up to that 750 yards but will have more drop at all points beyond 750 yards. Increasing alittude produces an effect more like increasing the bullet's BC than like increasing the bullet's muzzle velocity.

Whatever you choose to change that you input to the Eliminators software I would suggest that you test what the Eliminator predicts against where your rifle actually shoots at some other distance, perhaps 400 yaards. The objective is to have the Eliminator predict the actual bullet drop at any distance.

5. ### TXBodeanMember

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12
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May 31, 2012
Not familiar with JBM ballistics but if your software bullet drop is accurate at your established altitude, then just use it to set the Eliminator bullet drop at that altitude. When you change altitude, enter what your software gives you for the 750yd drop at that altitude in your Eliminator setup.