A friend recently mentioned that he had tried out some “sub-sonic 9mm ammo” that was supposed to be good for use in USPSA Production class shooting. He asked me what I thought, which resulted in the following response.
Before I comment on subsonic ammo, a few words are in order:
As a competitive shooter, one of the key reasons for reloading is to work up a tuned round specifically to work with one’s tuned pistol to produce shots with little felt recoil that still achieve minimum power factor for the division one is shooting. In our case (Production division) everyone is scored Minor Power Factor (MinorPF), so there’s no advantage to loading higher than that. Minimum MinorPF is 125. This is Mass (bullet weight in grains) times velocity divided by 1000. So, if you are shooting 115gr bullets at 1100 feet-per-second that equals a PF of 126.5, or just over the minimum for Minor. Most factory ammo is hotter than this, which results in a higher PF but also much greater felt recoil. Shooters desiring less recoil and more control can achieve this by trading velocity for bullet weight. Continue reading “USPSA: 9mm bullets for Production – what weight?”
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