17 HMR is a rimfire.

17 Rem is a centerfire based off the 223 case, shoulder moved back and necked down to 17.

17 Fireball (created in 2007) is better case-to-bullet effiency with less blast and nearly the same velocities as 17 Rem. Uses a lot less powder (less heat, less fouling).

Last edited by BlackFrog; 01/19/11.