Here's the RadioShed MSDS for their etch.
https://cdn.shopify.com/s/files/1/0953/5...314291674007590It shows the Ferric Chloride % at anywhere from 30% to 60% (??) ...unless I read it wrong! wouldn;t be the first time.
The hydrochloric acid content is 1/10% to 1.0%
Kind of hard with that wide range of 30 to 60% to dilute it to anything specific.
The stuff I use I bought off of  EvilBay some years back. It;s  marked as a specific % soln,,forget what it is. 
I use it diluted to about 3 or 4% for damascus finishing