Last year I embarked on a quest to get the old 30wcf to shoot cast with real powder.
The rifle groups great with the heathen powder and copper bullets.
The rifle hates cast bullets, I tried different bullets, in different hardness, smokeless and real powder.
It would never give a group smaller than 12" at 100 yards, with cast,
I read that the old nickle steel barrels would do just that, sorry I can't help you pard.
Here is a pic of the fine old rifle and a Spring 2005 ( dead) Rio Grande .