US MANUFACTURED BORE CLEANING SYSTEMS SMALL CALIBER KITS ARE DESIGNED FOR THE 20mm-50mm BORE SIZE US MANUFACTURED BORE CLEANING SYSTEMS LARGE CALIBER KITS ARE DESIGNED FOR THE 76mm-155mm BORE SIZE OCS TRAVELS TO THE U.S.S. COD FOR DEMONSTRATION See our Media tab for a demonstration video. OCS SUPPORTS OUR TROOPS To those that Serve, To those that Support, To those that Sacrifice. May Freedom always Ring. ISO 9001 2015 Certified Ordnance Cleaning Systems is proud to announce that we are now ISO 9001 2015 Certified. Thank you to everyone that helped achieve this goal. Interested in Vibrating Bore Brushes? Support a small business with a Maintain your Aim bumper sticker. Click on the logo to request your stickers.