Step 1: Break the clues into range clues and direction clues. Burning, blackening, and tattooing tell you the distance; the dirt collar tells you entry versus exit.
Step 2: Powder soot and grains only mark the skin when the gun is fired from close by, so the range here is close, not distant.
Step 3: A dirt (grease) collar forms as the spinning bullet scrapes dirt and lubricant onto the skin edge as it enters, so this is an entry wound. Exit wounds are ragged, everted, and have no soot or collar.
Step 4: Close range plus entry features together point to a single answer.
\[\boxed{\text{Close shot entry wound}}\]