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Some years ago, I developed a formula to calculate barrel life based on data from Sierra Bullets and top ranked competitive shooters experiences. It's based on match grade barrels testing 1/4 MOA average for 10 shot groups until average was 3/8 MOA. When powder charge weights were at bore capacity, barrel life was about 3000 rounds. Bore capacity is 1 grain of powder for each square millimeter of the bore cross section area.
Charge weights 40% more than bore capacity got 1500 round barrel life. Charges 100% more than bore capacity produced 750 round barrel lives. It's based on the inverse square root laws
Double the barrel lives for hunting rifles shooting groups 2 to 3 times as large. Triple or quadruple them for military service rifles shooting groups 4 to 5 times bigger.
Barrel life can vary 10% across powder heat indices, hotter ones reduce the barrel lives.
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