I thought I should clarify the difference between the Sako 5.7 x 43 against a regular .223 to clear up if ppl think it is the same as the .223 or 5.56 rounds.
So I dug out a packet of Bentley Sporting .223 and compared it to the Sako round and as you can tell there is a vast difference in the two rounds.
I included a pic of the packet as you don't see them around to often plus Bentley made more than just cars and shotguns.
Pic # 1 ~ .223 on the left Sako 5.7 x 43 on the right.
Pic # 2 ~ Bentley packet of 20 rounds .223 sporting ammunition.