Originally Posted by ithaca_deerslayer
Do these interchange .223 and 5.56 no problem?
Yep, the 6920 is good to go for both 5.56 and .223. If your rifle is chambered for 5.56, you can shoot both 5.56 and .223, but it is not recommended to shoot 5.56 in a rifle chambered for .223.
ETA: forgot to add another thumbs up vote for the Colt. Anything from Colt, BCM, DD, etc. would serve you quite well.