I have been to Butner many times but I couldn't give you directions myself. I can drive there but not give directions. But here is the NSSC website URL. Click on the "range info" link for a visual map and there are links for turn by turn directions also.
I have only fired 1 F-class match there and can't remember what range protocol is for practice firing and getting your drop settings. I would email one of the POCs from the website or maybe Rustystud knows himself.
My guns are all torn apart being reworked over the winter. So have fun fellas!! Sure hope it gets a little warmer!! ;)
North State Shooting Club