Hey guys just built a new AR. Using Hardened arms 16" M4 1/7 Melonite Tactical 15" Quad Rail and Spikes Lower. Gun shot great the other day using .223 winchester bullets. Today I used 5.56 Independence rounds and every 5 or 6 rounds bullet gets jammed and I have to pull the charging handle really hard to release the bullet. It happened 5 times with just 2 mags. I attached a picture showing how there are the same markings on the case of the bullets each time it happens. Bullets are also bent slightly.
Do i just need to go back to .223?
Upper is suppose to be able to shoot 556 and 223 all day.
Any help would be appreciated.