Well I´m not sure about how much .228 cal is. Where I live we count the caliber in millimeters.

First, it's .223 caliber. And, while I'm not an expert at this sort of thing, I believe that that's basically the US term for 5.56 NATO ammo, which is what's used in M-16s, but not the 5.56 Long ammo that's used in AK-47s. Actually, .223 and 5.56 ammo is slightly different, but they're close enough that some people use them interchangeably. And I wouldn't be surprised if it was impossible to tell the difference once the bullet has hit something. Anyway, the cartridge and charge behind .223 and 5.56 is very similar -- much different than that behind a .22 bullet.