john hammer mill detils MC World. JOHN Feed Grinders For Sale 20 Listings. john 14 hammer mill, 540 pto drive, stationary style, 14" in width, has a couple screens, hopper feed, three sets of hammers that are reversable for longer use, price $1995, also have a two wheel cart that will fit this or a john 43 corn sheller and is priced at $595get price.