Launched in 2004, The 204 Ruger was a joint development by Hornady and Ruger. It is based on the 222 Rem Mag case necked to .204”, with the shoulder mover forward and changed to 30º Using the 222 Rem Mag case instead of the 223 case, the 204 Ruger provides about 5% extra case capacity. It was also the first .20-caliber commercial cartridge launched by any manufacturer.
