IMHO the two cocking slides of the Blaser dr may be there for the same reason that led to the demise of Dreyse's and Berger's double needlefire actions 130 years ago: both guns used coil spring powered, inline strikers/needles like the Blaser. Both designs were cocked by pushing forward the locks with the thumb, cocking the springs. The Berger had seperate locks like the Blaser, requiring two pushes to cock both locks. In the Dreyse both locks were connected, so both were cocked by one movement. The Dreyse never made the conversion from needle- to centerfire with metal-cupped primers, while the Berger did for some time. Reason: The striker spring power had to be increased to dent centerfire primers. Berger's single locks could still be cocked,barely, by thumb pressure, while it was impossible to cock two marginally powerfull springs at the same time with a single push of the thumb. This may be the reason why Blaser uses two cocking slides to cock two springs.