What is Bj hunnicut real name on mash?

His full name is "BJ Hunnicutt"

The subplot of an entire episode consisted of Hawkeye trying to find out what the B. and the J. stand for. Hawkeye goes to such lengths as contacting friends and family of B.J., who all reply that they know his name only as "B.J." In the final scene, Hawkeye asks, "What kind of parents would name their kid B.J.?", to which B.J. replies, "My mother...Bea Hunnicutt, and my father...Jay Hunnicutt." OR If you are looking for the actors name, it is Mike Farrell.