Hi all, glad to have found this site. Been itching for a AR based 22lr and this site convinced me to go with the HK rather than a S&W. Picked up one this weekend at a local gun show. After putting some rounds thru it I am totally in love with it. What I would like to know is there a drop in trigger assembly to replace the stock trigger pack or is gonna be a take it apart and have it gunsmithed deal? Thanks! mike