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More on Ft. Lbs vs stopping power

Discussion in 'Uncategorized Threads' started by flinter58, Jul 13, 2007.

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  1. flinter58

    flinter58 TS Member

    Joined:
    Jan 29, 1998
    Messages:
    70
    In the previous thread on Ft. Lbs vs stopping power I don't think anyone gave a formula for stopping power - everyone prob. knows the formula for foot pounds of energy - Here is a formula I saw used to compare rifles for dangerous game, to calculate Knock Out Value - wt. of bullet in grains DIVIDED BY 7000 TIMES Muzzle Velocity TIMES bullet diameter in inches - or wt. in grain/7000*MV*dia.in inches. Run some of your favorite loads thru this and then compare the results to how you think thay stop game. In this case Size really does matter.
     
  2. Steve-CT

    Steve-CT TS Member

    Joined:
    Jan 29, 1998
    Messages:
    524
    "KO" value has long been refuted and so too, was the NIJ's "RII" (Relative Incapacitation Index) developed in the mid 1970s that was nothing more than mental masturbation. A formula based on nothing but giving weighting to velocity and whether or not a bullet was a hollow point.

    Under "RII" a score above "10" was considered acceptable. A .38 scored in the 5's a .22 rimfire scored a 3.7 and the .45 ACP scored a "2.6"

    A .380 or 9mm with a thin jacket 80-grain to 90-grain JHP at 1,200 fps scored in the teens. thin jacket, lightweight mid bore bullets
    have proven disappointing failures on the street - as the 1986 Miami Massacre proved.
     
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