To all, I was just playing around with some numbers on my ballistic program and was wondering what do the different drag functions represent? The program lists the fallowing as choices: G1 G2 G5 G6 G7 G8 GL GI What do these different functions represent. I assume they are scales for different types of bullet designs but do not know for sure. I am most interested in which one to use for VLD types of bullets. Thanks for the time and information!!! Good Shooting!!! 50 [ 08-04-2003: Message edited by: Fiftydriver ]

Your assumption is essentially correct, the higher "G" numbers representing lower drag form standards for comparison. The link above offers a decent explanation. "VLD" is a term not a specific design. Any data you derive from the Ballistics Programs with inserted 'G' values will be an approximation(perhaps close) that will need verification at the range.

After reading the site that 700 posted it looks like g5 or g7 would be what you would use for the 300gr MK. I ran the calculations and they seem way high. I understand that any chart will have to be customized but would the g5 drag function be closer to the bullets performance then say g1 which seems more reasonable? ** nevermind after reading around on the sierra site I found the info I needed ** [ 08-06-2003: Message edited by: Pennell ]

You may find additional info of use in "Hatcher's Notebook", "Modern Exterior Ballistics", or www.nennstiel-ruprecht.de/bullfly//index.htm#Formulas Anybody know what happened to the JBM webpage? [ 08-06-2003: Message edited by: MAX ]