At SHOT Show 2010, SIG showed their new Model 516 and 716 rifles to the industry. The 516, a short stroke tappet version of the M4 was released to compete in the military and law enforcement markets both world wide as well as the U.S. With the direct gas versus piston operated controversy, SIG decided everyone is making a direct gas gun, why not then make a high quality piston operated rifle to satisfy those who have the piston bug. The 5.56mm SIG 516 is an M4 carbine with the only major differences being….