A quick glance at the ballistics tables from an older Sierra load manual, shows that the 6.5 with their 140 gr bullet at their listed max velocity of 2500, and a 100 gr 243 bullet at 2900, the only difference besides the .031 bullet diameter is the sectional density, 281 v .242.... other than that the fpe energy is close enough to call identical....

the most expensive bullet there is isn't worth a plug nickel if it don't go where its supposed to.
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