As you are going up hwy 17 there is Carolina Rod and Gun, it will be on your right near all of the big car dealers, it is in the same building as a bike shop, Charleston Bicycle Shop, I believe. I do not know about their powder and primer stock???
There is one other shop that carries re-loading goodies but it will be way out of your way.
I went past you last week from Charleston, I'm at Kings Bay right now until tomorrow. Enjoy the ride!
You are most welcome. Last visit I made, they did have some cool stuff, couple of 700P's, couple of SPS T's, not a bad selection of Black Rifles, good optics selection for a shop, guys are real nice and helpful. A lot of there weapons are consignment.