Umm, no. Bad choice
Ignoring the fact that Bushmaster isn't exactly known for quality, choosing an AR that is chambered for .223 doesn't make any sense. An AR-15 rifle chambered for 5.56 can safely shoot both 5.56 and .223 while one chambered for .223 can only safely shoot .223. Why would you buy a gun that can't use the 5.56 which is far more readily available?
Don’t know - have had my bushmaster for years and never ever a problem yet