The unusual nature of pronghorns and the open habitats they roam suggest a fast, flat, wind resistant cartridge and bullet combination. Is the best a 6mm, 25-caliber, or 6.5 caliber?

The 6.5x57, Paul Mauser’s take on the 6.5mm caliber, preceded todays 6.5mm mania by more than 120 years, yet this “antiquated” cartridge outperforms many of today’s 6.5mm darlings and runs neck and neck with others.