Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Rifles, Bullets, Barrels and Ballistics


Reply

#####Ballistics HELP (PLEASE)######

 
LinkBack Thread Tools Display Modes
  #1  
Old 11-17-2012, 07:36 PM
Platinum Member
 
Join Date: Jun 2009
Posts: 1,654
#####Ballistics HELP (PLEASE)######

If it wasent for some of you guys like Broz , Shawn and others I would throw my NF ballistics software in the garbage but I have seen photos and video of you makeing extremely long shots so I know it is me but I dont have a clue as to what to do. .... As you can tell im a little frustrated. I need help . I cannot get my program to give me the correct elevation dope .

Example : The last time I shot was at 556 yards ( not that far) so I thought I would atleast be within the 8" circle that I was shooting at .
I shot a 3 shot group it measured 5" from center to center , I then measured from the center of the group to the center of the bulls eye and it measured 8" high. I can handle being left or right because that could be my wind reading skills but my confidence is lacking on the elevation dope that my program is giving me .

A question or two and then I will give you all of the details concerning what I had entered into my program the day that I shot.

1. How close can you get to center of the target with your program at this distance ? What should I exspect or what is the norm ?
2. Just throwing this one out there , I have never calibrated my Kestrel 2500 NV . Is it possible that its not giving me precise info to input ?

Now the details of my load and the conditions for the day of the shoot.

210 Berger
Rem Brass
Fed 215M primer
85.5 Grains of Retumbo
300 RUM

Elevation 693
Temp79.0
R.H 62.0
Baro 29.18

Yardage 556
MV 2900

NF called for 8.50 MOA up.

Note with my program it has a box with a check in it, to calculate the standard pressure and I clear it out . Im pretty sure this the correct way.

Almost forgot that this is a new pound of powder with different lot number.

Let me know your thoughts I will greatly appreciate any help .

I dont have a cosine indicator yet and I was on the top of a ridge shooting down hill. Would this have made me hit high ?
__________________
"Molon Labe"
IN DIXIE WE DON"T CALL 911 !
Reply With Quote

  #2  
Old 11-17-2012, 08:13 PM
Platinum Member
 
Join Date: Mar 2008
Location: SW Idaho
Posts: 1,151
Re: #####Ballistics HELP (PLEASE)######

What is your zero range?

Atmoshpheric conditions will havealmost no impact on POI inside 5-600 yards so something else is likely wrong.

I don't have and NF (exbal) experience but can run some numbers for you on Shooter.

As a reminder there is a free ballistic program here at LRH and it is a good one. Look at the top in the brown heading bar under G7 ballistic calculator.

Scot E.
Reply With Quote
  #3  
Old 11-17-2012, 08:17 PM
Bronze Member
 
Join Date: Dec 2010
Location: Alabama
Posts: 99
Re: #####Ballistics HELP (PLEASE)######

Shooting down hill will make you hit high, hastily running your ballistics on the G7 coefficient @ 550 yds 20 degree angle about a minute off, 30 degrees= an tad over 2 minutes off.
__________________
If I had to choose between taking a civilian or POG on a patrol, I'd happily take the civilian. At least he hasn't made the conscious decision of being a coward in the military yet!"
-Carlos Hathcock SS Vietnam USMC
Reply With Quote
  #4  
Old 11-17-2012, 08:19 PM
Silver Member
 
Join Date: Aug 2009
Location: British Columbia Canada
Posts: 166
Re: #####Ballistics HELP (PLEASE)######

Shooting up or down will make you hit high. If you can figure out the angle you should be able to find a online program to tell you how much. 8 inches at almost 600 yards seems plausible to me though
Reply With Quote
  #5  
Old 11-17-2012, 08:39 PM
Platinum Member
 
Join Date: Jun 2009
Posts: 1,654
Re: #####Ballistics HELP (PLEASE)######

My zero is at 200 yards.

I used a B.C of .631

Thanks guys for trying to help.
__________________
"Molon Labe"
IN DIXIE WE DON"T CALL 911 !
Reply With Quote
  #6  
Old 11-17-2012, 09:18 PM
Platinum Member
 
Join Date: Feb 2007
Location: Townsend, Montana.
Posts: 7,904
Re: #####Ballistics HELP (PLEASE)######

First recheck zero. I recommend you go to a 100 yard zero. Then change the program to 100 yard zero. Reason is if your groups are 1 moa it will leave more room for error at 200 than 100. Then shoot groups at 500, 700, and 900. Record the field conditions. Then record what you dialed for each group and also how low or high the group center was from point of aim. If a group is abnormally large shoot it again. Once you have this data you can figure what you actually needed to be spot on for center group. Example: The center of group at 700 yards was 3 1/2 " low of point of aim. You used 18 MOA for a dial up. 3 1/2" at 700 is 1/2 moa. So you needed to dial 18.5 moa. Record now what the spot on dial ups should be for each distance with those field conditions. Then using G1 BC of .631 change muzzle velocity in exbal until all match within .25 moa. If you can not get them all on, go for making the farthest ones perfect. If you can't get them spot on remember the accuracy error of your combination. (shooting skill, ammo quality and rifle accuracy)

A 5" group at 556 yards is almost 1 moa. That is not great so it might be hard to get all 3 perfect. Once you get it close then with your newly calibrated program shoot some more at differences and fine tune if needed. Remember!! It is better to be 1/2 moa off at 500 yards than 900. Because 1/2 MOA at 500 is a 2 1/2 " miss at 1000 1/2 moa is a 5" miss.

PS: I have used that .631 BC for many .308 cal rifles with 210 VLD's. It has always worked well out to 1200 yards.

My rifles shoot spot on to center of group within the combinations accuracy. That is 1/2 MOA to 1500 on an average.

Yes a slope will make you go high. But it would have to be a pretty steep slope at 556 for 8".

There is a reason I buy powder in the same lot and 40 lbs at a time.



Jeff
__________________

Last edited by Broz; 11-17-2012 at 09:56 PM.
Reply With Quote
  #7  
Old 11-17-2012, 09:48 PM
Platinum Member
 
Join Date: Jan 2008
Location: West Central Idaho
Posts: 1,119
Re: #####Ballistics HELP (PLEASE)######

I just ran your dope in Exbal and got the same results. Then I punched in a 25 degree slope and there was about a 8 inch difference. So I would guess that the slope you speak of is the culprit. 25 degrees is not a lot of slope. Your velocity may have changed a little either way with the new can of powder?? I'm assuming you have verified the drops beyond the 550 right?


That's all I got....sorry.
__________________
Jim



There is something about the outside of a horse that is good for the inside of a man. Sir Winston Churchill.

Everything that is really great and inspiring is created by the individual who can labor in freedom. Einstein
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: #####Ballistics HELP (PLEASE)######
Thread Thread Starter Forum Replies Last Post
Ballistics app sean1 The Basics, Starting Out 4 11-19-2011 11:37 AM
.223 ballistics gremcat Rifles, Bullets, Barrels and Ballistics 6 05-05-2008 08:42 PM
223 ballistics roundss Rifles, Bullets, Barrels and Ballistics 2 04-22-2008 03:54 PM
338 Lapua Mag Ballistics (Black Hills 250 gr ballistics?) EYESOFTEXAS Rifles, Bullets, Barrels and Ballistics 1 12-07-2005 02:12 PM
6MM Ballistics dbhostler Rifles, Bullets, Barrels and Ballistics 11 10-24-2003 02:49 AM


All times are GMT -5. The time now is 06:53 PM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC