Just found this in the shootin times,
The minimum calibre to be used against wild boar is the .270 Win, delivering a muzzle energy of 2,700ft/lb, but it is recommended that a calibre of no less than 7mm with a bullet of 160 grains-plus and muzzle energy of no less than 2,800ft/lb should be used.
I know this isn't what you asked, but it warns against using 223 or even 243 as they are that tough and could cause a potential dangerous situation with a wounded animal.
If you already knew this then good luck if not then its a heads up, Keep us posted.