Calculate BC from Point of Impact

Calculate BC from Point of Impact

This is a discussion on Calculate BC from Point of Impact within the Fieldcraft forums, part of the Field & Tactical category; I have an app for pellets (chair gun) that allows me to calculate the BC of pellet guns using point of impact, but it errors ...

Results 1 to 5 of 5
Like Tree1Likes
  • 1 Post By NorCalFocus

Thread: Calculate BC from Point of Impact

  1. #1
    Junior Member
    Join Date
    Dec 2016
    Posts
    5

    Calculate BC from Point of Impact

    I have an app for pellets (chair gun) that allows me to calculate the BC of pellet guns using point of impact, but it errors out at higher velocities and with POI over 100 yds because it isn't designed for rifles.

    Anyone know of a program for rifles?

    Thank you for your time.

  2. #2
    Super Moderator NorCalFocus's Avatar
    Join Date
    Jul 2013
    Location
    Surprise, AZ
    Posts
    4,710
    Quote Originally Posted by zt11299 View Post
    I have an app for pellets (chair gun) that allows me to calculate the BC of pellet guns using point of impact, but it errors out at higher velocities and with POI over 100 yds because it isn't designed for rifles.

    Anyone know of a program for rifles?

    Thank you for your time.
    LRBC Tool on Vortexes website. Put in your info (take your best guess at all the info) and print out a chart. You go shoot, measure your drops and take note of all the weather. Go back to the LRBC and use the validation option. It will give you a calculated BC and MV.
    zt11299 likes this.
    -I redefined trust between my wife and I. I bought her a gun, taught her to shoot, and made her the beneficiary on my life insurance.

  3. #3
    Junior Member
    Join Date
    Mar 2017
    Location
    Az
    Posts
    15
    There are some great apps i use chair gun for air rifles then for my powder burners i use strelock pro, appplied ballistics, ballistic arc, and lapua when im looking for a first round hit i used my log book and applied ballistics with ballistic arc and check the numbers against each other if everthing matches i fire it takes alot of data collection to make the apps work to there true potential but i recommend ap or ba if you are willing to pay for free strelock paid strelock is good too

  4. Remove Advertisements
    SniperForums.com
    Advertisements
     

  5. #4
    Member
    Join Date
    Apr 2014
    Location
    South Carolina
    Posts
    72
    I like Knight's armament's bullet flight (M) app. It has a bc truing feature.

  6. #5
    Senior Member ddd oo7's Avatar
    Join Date
    Mar 2011
    Location
    Memphis, TN
    Posts
    5,109
    The problem with this method is that one is playing with a fixed "variable" as if it is changeable. Ballistics calculators work...and work well if they are fed all of the right information. Now...when they don't work it is usually because someone guessed at the temperature, humidity, muzzle velocity, BC, etc. Now...with most of these numbers all one can hope to do is to get close. I might know the temperature within 2-3 degrees and the humidity within 3-5%. I might know my velocity...but it might vary from 5-10 fps or more. Ballistics Coefficient should be a "written in stone" known variable. Ballistics Coefficient changes typically with bullet speed...but not much else.

    Now...If you don't know the BC of the bullets you are using it is POSSIBLE to figure backwards with a ballistics app...but it is only accurate if every single other variable is also accurate. Teh only way to know if every single other variable is also accurate is to check poi against the ballistics app at several different distances. If you are willing to take the time to check poi at several different distances...you can record your results and then you don't have a lot of need for the ballistics app.
    Desert Tech SRS A1 with TS Customs 308 win, 22 CM, and 7 LRM barrels
    Primal Rights 40x .22LR Repeater
    NRA LIFE MEMBER
    Hidden Content

Ads

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Similar Threads

  1. Replies: 9
    Last Post: 12-14-2015, 11:58 PM
  2. point of impact on variable power scopes
    By krhudson65 in forum Optics
    Replies: 2
    Last Post: 09-26-2010, 08:26 PM
  3. SHIFT IN POINT OF IMPACT!
    By wjstewart in forum SOP
    Replies: 6
    Last Post: 06-06-2010, 03:56 AM
  4. Point of Impact at 100 Yards
    By thornblom in forum Rifles
    Replies: 5
    Last Post: 11-13-2009, 08:22 AM
  5. Replies: 26
    Last Post: 06-08-2007, 05:44 AM