I didn't say barrel length changes the twist rate. I was trying to explain why pistol barrels need a faster twist. Since that's how they come it seems to be correct.
The velocity difference is a given and I didn't think it needed to be mentioned. You didn't understand why pistols come with a faster twist. I tried to explain why.
btw Speaking of twist and a bit off topic, but when I talked to Green Mountain about their barrels I was told they worked a long time to come up with the sweet spot for twist rate and barrel length. The 32" barrel with a 1-70 twist was the best combo they came up with. Along with the dimensions of the rifling. I know the one I had was the sweetest shooting PRB barrel i've ever tried.