Hey Monz!
Have not got any data for the 300 gr. Swift, but V�penjournalens "Ladeboken" gives data for the 293 gr. RWS TUG. It is not far away in weight, but probably a little bit softer, giving the possibility to use a little bit more powder behind it. My experiece is that the Swift A-frame is a little bit harder than conventional bullets, which gives higher pressure with a given load for a softer bullet.
Ladeboken gives this data for the 293 gr. TUG:
Whitav. N135:
50 gr. 2136 fps/651 m/s
52 gr. 2229 fps/679 m/s
Norma 201:
50 gr. 2159 fps/ 658 m/s
53 gr. 2288 fps/ 687 m/s
Whitav. N140:
53 gr. 2235 fps/681 m/s
55 gr 2295 fps/700 m/s
Norma 202:
54 gr. 2287 fps/697 m/s
56 gr. 2337 fps/712 m/s
Carteridge-length: 85 mm
Lowest and max load shown. I take no responsibility for your reloading, but myself I would start 15-20 percent lower than the maximumloads shown with the 300 gr. Swift, and work it up.