pulled from 6mmBR site
FREE Ballistics Calculators And Data Charts from Canada’s NFA
Filed under: Tech Tip, ▫Articles — Tags: ballistics, Smallbore, Twist Rate — Editor @ 6 am
Ever wondered what twist rate is required to stabilize a particular bullet? Or would you like to see how changes in spin rates (rpm) affect bullet stability? Well thanks to our friends from Canada, you’ll find helpful formulas online that answer many questions about external ballistics.
The Ballistics Page for the Canadian National Firearms Association (NFA) website offers a variety of useful programs and data charts created by Peter Cronhelm. These include:
Caliber Twist Rate Chart
Greenhill Formula Twist Calculator
Bullet Stability Calculator (requires MS Excel)
Ballistic Coefficients Chart (MS Word), (Or DOWNLOAD HERE.)
Ranging Ballistics Computer (Scroll to bottom of page.)
This exterior ballistics computer works in conjunction with range data as well as computing a conventional drop and windage chart. Using an FFP (Final Firing Point) and multiple TRP’s (Target Reference Points) the system will simultaneously calculate Drop and Windage data for up to 30 TRP’s 360 degrees around the FFP. Windage is corrected for the TRP direction compared to the primary wind direction. The spreadsheet consists of six individual pages. Each page performs a distinct function and contains all the information required to complete a shot at a target or targets. The entire system can be used in any laptop or handheld computer capable of running MS Excel or Excel CE.
CLICK HERE to download Ranging Ballistics Computer (requires MS Excel)