I use a 22 lb spring with 45-08 and might/could/should go to a 24 lb. 30 lbs is far more than needed IMO, especially for 45 Super, which is "powder puff" compared to 45-08. A 30 lb spring would be too much to cycle the action for all but the stiffest loads (if at all with 45 Super) and would place a lot of unnecessary stress on the gun. I bought the springs direct from Wolff - I suggest you buy one of their extra weight "packs" so that you can experiment.
Concerning the 45-08, making brass and loads, search on "45-08" and you'll find some good info here on CGN.