Just took a look again to verify #s & I was correct with first post.
Lyman's Cast Bullet 3rd edition shows velocity at 912 - 1147
My Hornady3rd edition shows that 240 SWC at 6.7 - 8.5 (800- 1000 fps)
Sure could be the difference in a cast vs a swagged bullet. Cast can take velocities that can make swagged bullets drip.