Igman 5.56x45mm NATO Ammunition IGM556M193 55 Grain M193 Full Metal Jacket -- Reliable ammo and fire accurately, zero misfires from factory matched magazine for Ruger AR556. Amend2 5.56x45 NATO / 223 Rem 10 Rounder A2556MOD2BLK10 -- DO NOT BUY FOR Ruger AR556. Factory match are from DuraMag 5.56/.223/300BLK AR (STAINLESS STEEL). NO RETURNS IF ORDERED. Outdoor Limited always ships perfect orders and beautiful packaging without ever any damage to parcels. The wife and I absolutely love Outdoor Limited. Also, thank you Outdoor Limited for your prompt email responses. You are truly appreciated :)