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.