New to me anyway. I keep one of my 22 mags handy to use off the back porch to take care of potential varmints such as coons, skunks, coyotes, etc. Distance is 95 yards from the porch to the woods. Always thought the 22 mag would be iffy on a large coyote so did some research and found out Blue Dot was a recommended powder to use for reduced loads in a .223. Loaded up some 55 grain Sierra spitzers to use in my CZ 527 lefty (1 in 12 twist). Powder charge was 12.5 grains. The noise level was on par with the 22 mag (according to my wife who was doing needle point when I was shooting). Accuracy? Pretty dang good, pretty much every shot touched each other at 51 yards which is what my bench is set up for. Velocity is estimated at 2,500 fps and I can get 560 loads out of 1 pound of powder.
I bought the bullets decades ago and the sticker on each box said $3.49.
Bullet $.03.5
Primer $ .03.5
Powder $ .04.3
Round it off to $.12 a round. That is $6 per 50. Half the price of 22 mags with a bigger bullet going faster. Yea, I know the bullets I used were really cheap but even if I had to buy bullets at todays prices it still is just as cheap to do this compared to buying 22 mag ammo. Less bullet drop, more power, and superb velocity. Win win.
Note: Be very careful you don't double charge a case.