1. D

    Rifle Scopes Change scope zero with altitude change

    Bullets are hitting the bullseye at 200 yards at altitude of 5,500 feet. Scope elevation knob is set to zero. If I do not change the scope elevation knob; then, bullets will hit some unknown distance below the bullseye at 200 yards at altitude of 3,000 feet. How many MOA do I need to turn...
  2. busapilot

    Where did the JBM websites go?

    Tried the JBM main page, getting error # 1500 temporarily unavailable. All the specific links return not found message. I just reloaded the browser in my Phone & was going back to replace all my lost cards. Hope they aren't lost for good...
  3. 45-70-500

    Range Report JBM question

    Another newbie question.In the JBM calculator do I enter the 20 MOA difference in my scope base under Elevation or does it not matter. I've tried entering it but the end result between this and entering 0 is the same. Was out for the first time last night on the DND range shooting 600 metres...
  4. BryanLitz

    Range Report JBM Update: Measured BCs added to bullet library

    <span style="font-size: 14pt">On behalf of "JBM Small Arms Ballistics" and "Applied Ballistics, LLC" I would like to announce the addition of measured BC data to the JBM bullet library.</span> For those who are not familiar with the free JBM online ballistics calculators, this is an excellent...
  5. SAS_Sniper

    Range Report ballistic calculator JBM

    http://www.eskimo.com/~jbm/calculations/calculations.html very very nice and precise... for drop,wind,energy and created ballistic card
  6. Doc Holiday13

    Range Report Proper Use of the JBM?

    Well I've been trying to stretch my wings with my 6.8SPC. I don't have a chrono, but fortunately for me I just recently downloaded a ballistics calculator for my motorola Q so it help a lot. I input all my data with the numbers I found posted about the 6.8SPC and bullets I was using I basically...
  7. S

    Range Report JBM Calculator and 20 MOA bases

    Is there a setting in JBM for 20 MOA bases?