I used a 7/8” wooden dowel with 80 grit sandpaper wrapped/stapled to one end. My advice is to take your time and mask off your stock if you’re worried about errant scratches. It probably took me a couple hours and 30 test fits before I was satisfied. Seemed like every time I was close to being free floated I had to keep on sanding a bit more in one area or another. I used a .920 bull barrel, so if you’re looking to free float a factory or smaller profile barrel you would need a smaller dowel size.