I know hammer and chisel isn't vogue anymore. But I had a ring of 1026 steel. 4.0 inch o.d., 3.5 i.d. (.25 wall) and .600 inches long. So this morning I grabbed hammer and chisel and cut through the first side in 41 hammer blows (single handed hammer). The second side took me 34 blows (to cut it in half). This took me less the 15 minutes. If you don't know what to do with your cannon plug. You could try a similar experiment. It might give you some ideas.