Fred Eichler Series Predator LAR-15M FE1015 With RRA Operator CAR Stock. The .223 Wylde chamber was designed as a match chambering for semi-automatic rifles. It will accomodate both .223 Rem and 5.56mm NATO ammunition. It is relieved in the case body to aid in extraction and features a shorter throat for improved accuracy. Additional features include a mid length gas system stainless steel barrel with 1/8 twist RRA muzzle brake RRA 2-stage varmint trigger RRA winter trigger guard BCM Gunfighter charging handle and a free floating Fred Eichler series handguard.