Please Help With Using a Balistics Calculator

[HumbleEinstein]

Please help me understand how to use a ballistics calculator. I am trying to input data for two factory loads into a ballistic calculator, but I can't find any data on their proper ballistic coefficient or drag function anywhere. I have already done five shots on the chronograph with both of them. Do I input the mean of the five shots as the muzzle velocity?

The two loads are:

1) Fiocchi 223C 62 grain -- It's listed on their website, but their is no ballistics data there or on the box.

2)Black Hills (new manufacture) 5.56 77 grain OTM -- This isn't even listed on their website for some reason. The closest thing to it is a .223 version.

I would also appreciate any other info I need that I have not yet considered. I need to get accurate results to fill out a long range qualification form for my range.

Thank you for your help.

 

[Pinecone]

Blackhill 77 gr OTM uses the Sierra 77 gr Match King bullet.

The .223 and 5.56 versions reported have the same MV. But if you shot it over a chrono, use what you saw out of YOUR rifle.

As for the Fiocchi, you may have to contact them for the BC of that bullet. Or with your chrono data, shoot it at 3 different distances, get your come ups from 100 yards, and try different BCs until you come up with what matches. Start with a 60 - 65 grain FMJ bullet from someone else.

 

[whisk604]

SierrA Claims .362 G1 for the 77 otm and the 62 is either .295 or .307 G1 depending on which bullet was used. always use your avg mv to get better results.