As an old coot, I'd like to point out that the velocities quoted in old publications could be charitably characterized as "optimistic". Velocities could be obtained by chronographs or ballistic pendulums and were few and far between. Also, the test barrels that allegedly produced the results were frequently longer than standard handgun barrels and there was no vent to simulate the barrel/cylinder gap.

Between that and improvements in current chronographs, comparison of old and new data isn't exactly apples to apples.