Starting to reload again.I've reloaded shells several times with out checking case length and never had a problem in my AR.Bought some once fired miltary brass and started checking case length.The cases varied quite abit.Took the longest case,resized it and dropped it in the barrel.It seated all the way in.Doe,s the military have a different case length than commertial,or is a 556 chamber different than 223?