Should I use a G1 or G7 form factor?

You should be using a Custom Drag Model, which is neither a G1 nor a G7. It is actually a representation of the actual bullet model against itself. CDMs (Custom Drag Models) ARE NOT G7 curves or segmented BC’s. However if you are going to use a G1 or G7, use a G1 when it’s a flat base bullet like the 22LR and 40 gr FB Varmint, use a G7 when it’s a boat tailed like the .308 185 gr Juggernaut and .243 105 gr Hybrid.

You can read more about this on our CDM Page, and in our Articles.