Welcome, okieboy. Good luck with your query. Most chunk matches are at 60 yards, while some, I understand are at 50 yards. The shooters lay down and shoot off a chunk - log, adjustable wooden rest - whatever. They mostly load at a table (I've seen in pictures), then walk forward, down into prone and prime, then shoot. This might have some imperfections in it, but is basically what it's about in most places.