One of the videos I watched the guy used the Otis cable cleaning system, I’m assuming the cable is vinyl coated?Yes, they take a special tool. Usually you never need to do anything to them other than put a little oil on them so they won't rust. I don't know if you've ever had another rifle that you can't clean the barrel from the receiver end. The the M1, on the M1A you have 2 options. You can use a pull-through cable system like the Otis or Kleen Bore kits or you can insert a cleaning rod at the muzzle. If you're going to us a metal cleaning rod be careful to prevent muzzle erosion caused by metal on metal contact. I use fiberglass rods on my M1s and M1As for this reason.