I've been loading plain base cast bullets for my .35 Whelen for many years, my use was limited to plinking only. When I first started I was using SR 4759, when that powder was discontinued I switched to Unique. 15gr. of Unique and bullets weighing 200, 210, 215 and 225 grains it didn't make any difference 15gr. of Unique was a load that shot very well accuracywise. Cast bullet loading adds what can be a fascinating new dimension to ones shooting, lots to research and experiment with.
