I'm not sure whether you're referring to Shooter's World "Blackout" or Hodgdon "CFE BLK." I've shot both this powders in my 300 Blackout, 20 VarTarg and 221 Remington Fireball w/ some success. I've not considered trying them in my son-in-law's 204 Ruger as I'd think both of those powders would be too fast. I'd think they'd be too fast for the 17 Remington, as well.