He straightened the hole by tapping the outside with a hammer. The bore needed to be reamed to a precise size and polished. To give a rifle ball a straighter shooting angle, spiral grooves were made in the bore. One of my favorite displays to see at a craft show locally is the tinsmith at work. The tinsmith was originally called a whitesmith.
Tin plate is a sheet of iron coated with tin to keep it from rusting.
It was originally made in small pieces, heated repeatedly and flattened. The oldtime whitesmith produced cylinders, boxes and cones of various shapes. If the finished product was to be a cup, he had to make a lip on the drinking surface. He made tin snips, tin dippers, candle boxes, tinder boxes, candlesticks, lamps, sconces, money boxes, tea caddys and more. His tools included a pair of large shears, hand snips and nippers.