Sundog. I recommend joining the Cast Bullet Association. I'm starting my second year.
You have me wondering about your friends 03A4. A lot of the WW-2 03A3's had two groove barrels. I've heard it said that they will shoot some cast bullets very well with two groove barrels.
Which bullets do you use? I've had good results from Lyman's 311291, sized to .310, and Lubed with lyman's Magic Orange. I load the .308 to about 1800 FPS with IMR-4895.
I load the same bullet to full power in 30-30 with WW-748.
I use IMR 4759 primarily in the 45-70 with the Lyman 457122 Gould hollow point bullet.
It does 2 to 2.5 inches at 100 yards in a Marlin micro-Groove barrel. Bullet is sized to .459 inch.