From Longman Dictionary of Contemporary Englishcrack shotcrack shotSHOOTsomeone who is able to shoot a weapon very well and hit the thing they are aiming at → crack
Examples from the Corpus
crack shot• And of course the doctor is a crack shot..• Dirk, nearly sixteen, is a crack shot.• A crack shot and a notorious gambler.• The book centres on young blonde Donna, a crack shot with a.45 Magnum. 