Drop charts - What's your procedure with details?

[djtjr]

Guys what are some of the tips and tricks you use in establishing your dope/drop charts? What are the details of your procedure from start to finish What are the variables you prefer to tweak to get theoretical drops to match up with field results. I feel like lately to get my field drops to match what my various balistic calcs say they should be based on velocity and bc I have to adjust velocity by well over 100 fps to get close. This is off an ohler so I am assuming its not that far off. Again that's all a starting point and you need to verify in the field and confirm dopes but in running a search I didn't find the level of detail I was looking for so wanted to see what are the most useful tips and tricks you guys have found fromo start to finish. Would you rather tweak BC which often isnt shown in a balistic calc but rather a hidden variable or tweak velocity to match things up? Or would you rather just get actual drops at a few yardges and tweak both till you get them to match up as closely as actual field drops. Any thoughts or details on your procedures from start to finish would be very helpful.
Thanks and all the best,
Don

 

[kelbro]

For me, actual drops are all that matter. The rest is just entertainment.

 

[FeMan]

I shoot tactical and with the varying ranges find I have to use a ballistics program to fill in any missing yardages. If you have a measured MV you feel is accurate and all other inputs are sound, I would tweak the BC. Make sure you have a MV for the temp you are shooting when you are calculating though. Some powders are very temperature sensitive.

 

[Grimstod]

Use a ballistics program. There are some good phone apps and some online resources too.

 

[CharlieNC]

Depending on caliber, the drops become more dependent on atmospherics beyond 500 yards. Be sure you have good atm for input before truing something else which is not off.

 

[brian427cobra]

This works perfectly
http://www.arcanamavens.com/LBSFiles/Shooting/Downloads/DA/

I use a Kestrel but with a little practice this works too
http://www.arcanamavens.com/LBSFiles/Shooting/Downloads/ManualDA/

 

[Screamineagle]

I use Vortex's ballistic program. You can find it on their website. I have found it to be very good, as long as all your inputs are correct. It also has a place where you can input your field results to create a perfect chart!
Steve

 

[Witchhunter]

I shoot mine at all ranges and use a tape to measure drops. No guessing or looking inline, tape it to the stock or the scope. Maybe not as precise as some but it worked for me for over 40 years....

 

[6xc-Longshooter]

Use JBM Ballistics---temperature-humidity and elevation are critical for long range--it works--keep trying.

 

[K22]

I couch my comments in terms of a varmint / predator hunter.

Know thy rifle is my motto.

I test my rifle / load combo at various ranges in which I expect to hunt. I establish the initial drop data on calm, cloudy days to avoid wind and mirage effects. This gives me a baseline which forms the basis of my drop chart.

I practice in varying climatic conditions of wind, temperature, and cloud cover to learn the affects and how to adjust under varying field conditions.

In my experience published drop data has little value unless validated in the field with your specific rifle / load combo.

 

[dragman]

Assuming the load is done and perfect.
Zero rifle @ 100 yards
Shoot a group of 3 on paper at over 1000 yards (take enough sighters to get you on then let it fly)
Go too JBM ballistics and put numbers in since you know exactly where you hit at a given distance at over 1000 yards then adjust your speed to make the drop chart comply with what you verified in the field. If I can verify it takes me say 27.25 MOA to hit 1250 yards then when I adjust my speed in my chart to duplicate that it works for as far as I can possibly shoot.