Quote:
|
Originally Posted by longrange1947
That is why alot of the ballistic "predictor" programs fail as they do not take into account that the BC changes with velocity. Sierra, atleast, shows three to four BCs with speed envelopes to get a basic prediciton. Presicion Workbench uses a modeled curve based on actual performance of your bullet/weapon combination at specific ranges.
As the velocity approaches trans sonic it falls off rapidly and then during subsonic shift it jumps back up. It flies really well but is very suseptable to any changes in air resistance as from wind shift to thermals. The round is spinning at a higher ratio to forward velocity so the round is now nose high and overstablized (gyroscopic) making it even more suseptable to violent tilts in axis, just as a gyroscope tilts once upset.
Predicitng bullet flight at those speeds is right next to impossible as so many things come into play.
|
Thank you, that is what I thought/leanred. I met some Greenill formula fanatics that told me I was FOS.
Thanks for the excellent read. My biggest mistake was sleeping too much in calculus class.