Drag Coefficient Tables
You can select from a number of drag coefficient tables (drag tables). The G1 drag coefficient is the standard for all center fire small arms bullets, and it seems to be the defacto standard for rimfire as well (RA-4 is the official rimfire standard). While the program has the ability to use up to twenty drag tables (they're just text files), there is seldom a need to use anything other than G1. If you are not familiar with the subject, just leave G1 selected. However, to select a drag table, click on the drag table select button (just to the left of the BC value). A dialog box opens that lists the available drag tables.
Click the drag table name you want to load and then click the OK button. The table is loaded and its name appears in the button to the left of the BC label. If you have selected a table other than G1 a message appears to remind you that G1 is the standard table. This message appears only once per session. After that a dialog box opens that gives you the choice of just using a B.C. value or converting to the selected drag function using either the equal drag or equal TOF methods.
Click the corresponding radio button to select the method you want to use and then click OK.
There's lots more information in Tutorial 4 about drag functions and the means of converting them. Open the Main Tutorial page to access the tutorials.