Moving but stable? All loads for the .454 start at 7-1/2" with 300 gr running about 1750 max. Mostly less. so you have 42,000 RPM's. go longer to get 1750 and you have 52, 500 RPM's. A BFR revolver will spin a bullet from the .454 at 78,750 RPM's.
You do not understand twist and velocities. How can a short barrel spin a bullet if velocity is lower? Twist is fixed but speed is not. You will never get 1750 FPS from a 2" .454. I don't even see your 1400 FPS, more in the 1100 range. .45 Colt.
You have been banned as I have but it was debating you for the most part. I am not wrong and never was.
