+1 for the sharpmaker. I use it on my bm-42A, bm 556/bm558. My buddies bm 555, bm 551. I use the 40 setting to sharpen them. Note if you are sharping the s30V, and it is DULL, you might want to try using a diamond hone first. The brown rods will take you literally HOURS to get it where it needs to be. Other than that, get the dia rods/ UF rods and youll be good to go.