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BC’s for non BC bullets

#2
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#4
Those calculators aren't the best but they work. With the JBM, if your measurements are off 1/4 in your BC will be off, and then what's the point.
Only way I know how to get an accurate ballistic coefficient is with an Oehler 88 or 89.
Lots of money or if you have a friend.
 
#5
We now can do this with today's ballistic apps. You just need a known velocity and approximate BC and verify/true the BC with the app at a known distance. Some apps will even calculate the bands.
 
#6
Thanks gentleman.

I have a Labradar so I can get the 2 velocities. Question about that:
For pistols is 1yd and 25yds enough distance? What about 1yd and 75yds for 5.56? That's about as far as it will track that bullet.

I found this site. Shooters Calculator Anyone have experience with it?

The gun data ballistic coefficient site doesn't seem to work. It'll only let me enter 3 characters, no decimal, and thus gives and error. If it worked I could see how this calculator may get me a decent BC for rifle bullets but how about for pistols?

Talk to me more about verifying. I have the Labradar and Ballistic AE on my iPhone.

Thanks again
 
#8
Verify consists of shooting a known distance with a good known muzzle velocity. AE is a little more complicated so I use Strelok. But I just shoot a 5 or 10 shot group at at least 600 yards. Select trajectory validation in the app. Plug in the true elevation based on my group. It may need to come up or down. Select BC rather than velocity and hit calculate. It will return with a BC number.

You don't need three digits for the online BC calculator. If it is .223 just enter .22. You just want a BC baseline to start with. On my end I can enter a decimal and two digits. That is all you need to estimate by math.

Also, somebody already asked but how is it you have bullets with no published BC to start off with?
 
#10
Okay, not exactly need a precise BC to start with. Just looking up a Hornady 62 grains is .274 G1. You can look up similarly with the others.
 
#11
Agree that I’m not doing Percision shooting with these rounds but my understanding is even a slightly different BC is going to give me drastic the different ballistic data Sure looks that way when I play with my ballistic A&E app
 
#12
Yes, it requires a little tweaking at range to fine tune. Most published BC are overstated a little and still need some work to narrow it down. It is a little more difficult at short range.
 
#14
It is your muzzle velocity. You have a good chrono so start with a good MV and estimated BC based on best available information. Pistol will need to be at shorter range. .223 @500 yards should be fine.
 
#15
Not 100% sure I understand what you’re saying. The labradar won’t follow a .2 to 3 bullet past 75 yards. Shooting a 9 mm bullet pass even 50 yards will problem cause problems with tracking with the LabRadar because of the amount of drop
 
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