Leroy James Sullivan is an American firearms inventor. Going by Jim Sullivan, he is noted as a designer of several 'scaled-down' versions of larger firearms. He is largely responsible for the Ultimax 100 light machine gun. He also contributed to the Ruger M77 rifle, and the M16, Stoner 63, and Ruger Mini-14 rifles (scaled from the AR-10, Stoner 62, and M14 rifle respectively). Sullivan has since 2007 become very critical of the M16 and M4 rifles that he co-designed.