Ballistic Check

[awleaphart]

Can somebody do me a favor and see if this is right compared to there Ballistics program. Also the Pressure # is what came in the program. Its a free program. (I'm low rent.) It seems to be shooting good using this chart. 284 Winchester. Thanks




I cant get it to Paste. Its in Excell.

 

[BryanLitz]

Your low rent ballistics are whack. Who knows what the ****** coefficient is, let alone the adjusted ****** coefficient or Meyewski constant...

Try this program:
http://www.appliedballisticsllc.com/BergerBallistics.exe

Use a G7 BC of .307 for the 162 Amax, or a G1 BC of .599.

No offense meant, I'm just having fun. Programs that use the Pejsa solution will always ask for bullet parameters (like the ****** coefficient) that no-one knows. If you stick to conventional BC's referenced to known standard projectiles like G1 or G7, then you can more effectively check your data with others.

Let me know if you have any trouble with the program,
-Bryan

 

[jerrschmitt]

Brian: Your program works great on my desk top but my netbook, running CE 5.0 doesn't recognize it. Do you have a program for the Windows CE hand helds/netbooks?

 

[BryanLitz]

jerr,

You need to have Java on the platform to run the program. Download this and the program will run.
Download Free Java Software - Sun Microsystems

-Bryan

 

[awleaphart]

Ok,
I am lost about the BC., Hornady says .625 for 162G 7mm Amax.
All I know at this point is 8.75 puts me on the mark at 500 yards. Can you back into that and tell me what you get in FPS and energy.

 

[awleaphart]

Sorry I need to read a little more into the post.

 

[BryanLitz]

awleaphart,

Now that you have Java, click on the link in my first post. That should download the program. When the download is complete, double click on the program and it will run. Input the bullet, atmosphere and sights data, select MOA output and click calculate.

-Bryan

 

[awleaphart]

I got it working. How did you get your BC's from Hornadys .625 to your G1 .599 and G7 .307.
I was getting around 2825Fps the day I was setting up my rifle. At the 500 yard range I keep shotting high. I need to be at 8.75 I was at 9.25 and I work back into the software in the FPS and kept moving it up until I got 8.75 and that put me around 2875FPS in the software.

With yours set at 2880FPS G1 .599 it gives me about the same reading. I have both software set at 1.75 for the scope.

 

[BryanLitz]

The BC's I gave you were measured directly by test firing, they're not related to Hornadys advertised numbers. If you're interested in how my BC's are measured, you can read about it here:
Book

I've got a few comments about your approach. Again, no offense intended here...

It seems like you're trying to use your drop data to come up with a MV and maybe a BC. This is not a good approach unless you've verified that your scope adjustments are true. For example, you say you need 8.75 MOA at 500 yards. What if your scope doesn't move perfectly as you think it does? What if your crosshairs actually move 9.12 MOA or 8.64 MOA when you have 8.75 MOA dialed on? This is more common than you might think. Also, did you measure the range to be exactly 500 yards, or is that just what it says on the sign? What I'm saying is that if you try to 'back-track' to find a missing variable in a ballistic equation, you have to be absolutely certain of all the other variables. Any uncertainty you have in atmospherics, range, BC, MV, scope clicks, or anything else will translate into uncertainty in the variable you're trying to identify.

Hope this helps. I'll be happy to discuss any of this further with you.

-Bryan

 

[jerrschmitt]

Thanks Brian.

 

[awleaphart]

Thanks alot for your help.
I my need to shoot throught the chrom again and check my scope tracking. I know I'm at 500 yards. Maybe I just need to buy the BOOK.
I have no way to tell what the pressure is the day I shoot. Thanks again.

 

[BryanLitz]

Good luck.

Knowing your MV is critical, as well as the value of your scope clicks.

Pressure can be estimated fairly accurately based on your altitude. If you use the 'standard' pressure at altitude you won't be very far off on any given day. Hint: if you hover the mouse over the word 'Pressure' in the ballistics program I posted, it will display a table of standard pressures for altitudes up to 10,000 ft.

Take care,
-Bryan