Not sure of your point. It wasn't the biggest round possible?
Would it or would it have not ripped out half the chest of a 30 pound kid?
I can't say if a .223 round could 'rip out half the chest' but I believe that the military equivalent (the 5.56mm round) has been known to 'tumble' on impact therefore causing serious amounts of physical trauma.
Some might argue that the 'point' might be your usage of the term 'high powered rifle' when in fact the firearm used is actually considered to be a low powered, light calibre gun. I do actually understand your anger for what might seem to be insensitive pettiness but I can explain a little further.
For the past several years now the media have been using terms such as 'sniper rifle', 'assault weapon', and 'high powered' to describe the firearms used as weapons in a criminal manner. They've been using these terms to further sensationalize tragic events when factually they're lying.
In this case alone I've seen the term 'high calibre' used in the media reports when in fact all the firearms reportedly used are small calibre guns. It has yet again stirred up a cry to ban 'assault rifles' when in fact the Bushmaster rifle used is neither high powered nor an assault rifle (not being a selective fire automatic/semi-automatic gun).
Technically, NONE of the rifles used in the Oregon mall shooting nor the Colorado theatre shooting were 'assault rifles' either, yet the media likes to push that perception.
The technical differentiation becomes an issue should the government decide to ban, restrict or prohibit 'assault weapons'. What might very well happen is that many firearms could be lumped together under a classification where they don't belong and be made unavailable, or restricted, for private ownership based on cosmetic appearance ONLY.
We know this is possible because this is EXACTLY what has been happening under Canadian laws for several years now. Prohibiting a firearm for it's cosmetic appearance only is not only an unjustified political move but it creates the facade of increased public security for those ill informed or willfully ignorant.
Consider if you will a government ban on pit bull ownership because pit bulls are considered a dangerous animal and must be removed from society. However, this ban will encompass the confiscation of all types of dogs from all of their respective owners because all of those dogs, are dogs, just like a pit bull...