6.5x55 data at modern pressures:
Nosler #6 manual, 23" barrel: 140-grain Partition, 2790 fps (52.0 H1000)
Ramshot on-line data, 24" barrel: 140-grain Partition, 2778 fps (49.8 Magnum)
6.5/.284 data:
Nosler #6 manual, 24" barrel: 140-grain Nosler Partition, 2906 fps (50.5 VV N165)
Hodgdon on-line data, 24" barrel: 142-grain Sierra Matchking, 2901 fps (49.5 Hybrid 100V)
These are all the top-velocity listed in each source of data. You'll find other sources will have the same sorts of numbers, IF they list modern-pressure 6.5x55 loads.
