Hey there:
I use this in: 22 Hornet, 222 Rem, 223 Rem. My reduced load I have used for years is:
55 Gr.FMJ read cheapest you can get
4.5 Gr. of Red Dot powder
This is about the same velocity of a 40 grain 22 rimfire
One year alone, I killed 22 big fox squirrels, one shot only with this in my 223 14" barrel with Leupold 2X scope
I also have chronographed this many times, my goal was to duplicate the 22 rimfire.
This load does not leave you with a two piece squirrel. They drop dead instantly, and you don't have to head shoot them, either. A chest shot leaves a small hole in, small hole out. No problem skinning the squirrels for the skillet.
I've also used Unique, Blue Dot, lots of other powders. I just happened to have a good supply of Red Dot, and I shoot often and a lot.
Best to you,
casper_zip
P.S. Forgot to mention, shooting from a rest, these will all go into a small hole you can cover with your thumbnail. The accuracy is amazing, and the noise is not bad, either.