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.