Leroy James Sullivan is an American firearms inventor. Going by Jim Sullivan, he is noted as the designer of several 'scaled-down' versions of larger firearms. He is largely responsible for the M16

M16 rifle

The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...

, Stoner 63

Stoner 63

The Stoner 63, also known as the XM22/E1, is an American modular weapons system designed by Eugene Stoner in the early 1960s. It was produced by Cadillac Gage and used in very limited numbers in Vietnam by members of the United States Navy SEALs and several law enforcement...

, and Ruger Mini-14 rifles (scaled from the AR-10

AR-10

The AR-10 is an American 7.62 mm battle rifle developed by Eugene Stoner in the late 1950s at ArmaLite, then a division of the Fairchild Aircraft Corporation...

, Stoner 62, and M14 rifle

M14 rifle

The M14 rifle, formally the United States Rifle, 7.62 mm, M14, is an American selective fire automatic rifle firing 7.62x51mm NATO  ammunition. It was the standard issue U.S. rifle from 1959 to 1970. The M14 was used for U.S...

 respectively) as well as the Ultimax 100

Ultimax 100

The Ultimax 100 is a Singaporean 5.56mm light machine gun, developed by the Chartered Industries of Singapore by a team of engineers under the guidance of American firearms designer L. James Sullivan. The gun is extremely accurate due to its low recoil.Work on a new light support weapon for the...

 light machine gun and Ruger M77

Ruger M77

The Ruger M77 is a bolt-action rifle produced by Sturm, Ruger & Company. It was designed by Jim Sullivan during his three years with Ruger. The rifle features a traditional Mauser-style two-lugged bolt with a claw extractor.- Design and features :...

rifle. Sullivan has since 2007 become very critical of the M16 and M4 rifles that he co-designed.