Non-corrosive steel cased .223 A great cost effective option for plinking!
https://www.westernmetal.ca/shooting/barnaul-223-remington-55-grain-fmj-bt-case-500-brn-223rem
https://www.westernmetal.ca/shooting/barnaul-223-remington-55-grain-fmj-bt-case-500-brn-223rem
