The above examples are ammo problems, not 223 vs 5.56 problems
Supposedly 223 ammo is safe in either 223 or 5.56 chambers. The alleged problems are when 5.56 ammo is fired in 223 chambers.
All the examples above were from defective 223 ammo fired in 5.56 chambers. That ammo would have caused problems in any gun.
The problem is greatly overstated. There are minor differences between the 2 rounds and in chamber specs, but if you check out any other commercial chambering you will find differences just as great. Same with chambers in different guns.
Lots of talk about different chamber pressures. My loading manuals show anywhere between 27,000 psi up to 60,000 psi as a max charge in 30-06 depending on the load. I've found a few factory 30-06 loads that simply would not fit in the chambers of certain rifles if you happen to get a rifle with a chamber cut on the minimum side and ammo a little on he large side. We could easily have 2-3 different designations for 30-06, but we don't.