CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.
1) .223 60 gr Hornady TAP bullet, 13 gr Blue Dot, 35 kpsi, 2500 fps. I have shot 1,000 varmints with this.
I have loaded it up to 15 gr Blue dot 50 kpsi, 2800 fps, but this is not needed.
2) .223 33 gr Hornady Vmax moly, 15 gr Blue Dot, 3500 fps. I have loaded up 5,000 rounds of these and killed may rodents.
I have loaded that up to 18 gr Blue Dot 4,100 fps, but this shows pressure sign half the time and is not needed.
The real advantage of Blue Dot in .223 is that the barrel never gets hot or dirty.
I can shoot 100 shots per hour all day with no cleaning, no heating, and great accuracy.
This Blue Dot in the .223 for rodents dates back to 1999 in The Varmint Hunter Magazine
http://www.jamescalhoon.com/tobee2.php