Most .223 chambers will fit most 5.56 cartridges, excluding those cases near the limits of 5.56 tolerance. There will be some 5.56 cases that won’t fit in .223 chambers. With that said though, only match 5.56 is worth shooting in a bolt gun and .223 is way more readily available and is a better fit for precision shooting. If you have an issue shooting 5.56 you can team the chamber, but I wouldn’t. .223 is a better chamber for precision than 5.56 if that is the goal.
5.56 has higher pressure that is measured differently than .223. It’s almost a meaningless point of discussion. There is zero difference in barrel construction. The same barrel dimension that shoots .223 on a Tikka is also the same profile that’s punched out for .300WinMag. Everything is the same except the machining f the bolt.