KIPR - Karcher Impact Performance (Refined)

About KIPR - KIPR was the culmination of trying to improve upon an old, and dare I say outdated, method of cartridge comparison. It started out as KIP, or Karcher Impact Performance, but as I tweaked the formula a bit to achieve smoother and more useful results, it morphed into KIPP (Karcher Impact Performance, Precise) and as of the latest iteration, KIPR. The idea is to compare not just bullet diameter and weight and velocity, but also include sectional density into the equation. KIPR also uses frontal area, in place of diameter.

This is far from a perfect equation, and at the end of the day, a successful hunt will always come down to shot placement over all else, but for those of us that like to get into the nerdy side of things, it’s an interesting way to compare cartridges, and as far as I know this is the first of such an equation formulated in the 21st century.

Provided here is a list of various cartridges and loads for comparison purposes.

  • 55GR @ 3200 ft/sec

    Kinetic Energy (Imperial): 1250.89 ft-lbs, (Metric): 1695.98 joules

    Sectional Density (Imperial): 0.158 lb/in², (Metric): 111.1 kg/m²

    Frontal Area (Imperial): 0.0391 in², (Metric): 0.0000252 m²

    KIPR Score: 77.19

  • 77GR @ 2800 ft/sec

    Kinetic Energy (Imperial): 1340.8 ft-lbs, (Metric): 1817.88 joules

    Sectional Density (Imperial): 0.221 lb/in², (Metric): 155.5 kg/m²

    Frontal Area (Imperial): 0.0391 in², (Metric): 0.0000252 m²

    KIPR Score: 115.84

  • 80GR @ 3350 ft/sec

    Kinetic Energy (Imperial): 1994.05 ft-lbs, (Metric): 2703.57 joules

    Sectional Density (Imperial): 0.194 lb/in², (Metric): 136.1 kg/m²

    Frontal Area (Imperial): 0.0464 in², (Metric): 0.00002992 m²

    KIPR Score: 178.99

  • 100 GR @ 2960 ft/sec

    Kinetic Energy (Imperial): 1945.98 ft-lbs, (Metric): 2638.4 joules

    Sectional Density (Imperial): 0.242 lb/in², (Metric): 170.1 kg/m²

    Frontal Area (Imperial): 0.0464 in², (Metric): 0.00002992 m²

    KIPR Score: 218.34

  • 127 GR @ 2825

    Kinetic Energy (Imperial): 2251.11 ft-lbs, (Metric): 3052.09 joules

    Sectional Density (Imperial): 0.26 lb/in², (Metric): 183 kg/m²

    Frontal Area (Imperial): 0.0547 in², (Metric): 0.00003532 m²

    KIPR Score: 320.77

  • 140 GR @ 2675

    Kinetic Energy (Imperial): 2225.01 ft-lbs, (Metric): 3016.71 joules

    Sectional Density (Imperial): 0.287 lb/in², (Metric): 201.8 kg/m²

    Frontal Area (Imperial): 0.0547 in², (Metric): 0.00003532 m²

    KIPR Score: 349.5

  • 130 GR @ 3000 ft/sec

    Kinetic Energy (Imperial): 2598.61 ft-lbs, (Metric): 3523.25 joules

    Sectional Density (Imperial): 0.242 lb/in², (Metric): 170.2 kg/m²

    Frontal Area (Imperial): 0.0603 in², (Metric): 0.00003888 m²

    KIPR Score: 379.03

  • 150 GR @ 2850 ft/sec

    Kinetic Energy (Imperial): 2706.06 ft-lbs, (Metric): 3668.92 joules

    Sectional Density (Imperial): 0.279 lb/in², (Metric): 196.4 kg/m²

    Frontal Area (Imperial): 0.0603 in², (Metric): 0.00003888 m²

    KIPR Score: 455.43

  • 140 @ 2950 ft/sec

    Kinetic Energy (Imperial): 2706 ft-lbs, (Metric): 3668.85 joules

    Sectional Density (Imperial): 0.287 lb/in², (Metric): 201.8 kg/m²

    Frontal Area (Imperial): 0.0547 in², (Metric): 0.00003532 m²

    KIPR Score: 425.06

  • 140 GR @ 3050 ft/sec

    Kinetic Energy (Imperial): 2892.55 ft-lbs, (Metric): 3921.77 joules

    Sectional Density (Imperial): 0.287 lb/in², (Metric): 201.8 kg/m²

    Frontal Area (Imperial): 0.0547 in², (Metric): 0.00003532 m²

    KIPR Score: 454.36