I'll add to that, that recoil is a major factor in speed, as some have already posted.
To actually test the speed, you'd have to get some guys together that were familiar with the actions being tested, and have all the various rifles, of the same weight, and using the same load, in the same cartridge.
For example, a 73 Winchester fired by a competent shooter familiar with the rifle, in 44-40, will easily beat, for aimed fire, any semi-auto, bolt, pump etc. sporting rifle you care to mention, if they were chambered in say 30-06.