Originally Posted by
Muley Hunter
Nobody mentioned stripping. A 1-70 twist barrel twist the ball one time in 70" of barrel. A 1-20 twist only needs 20" of barrel for one turn. Most pistols are only half of that. Let's say 10" of barrel. It only spins the ball 1/2 turn with a 1/20 twist. A 35" barrel will spin the ball 1/2 turn with a 1-70 twist.
So, they're both spinning the ball the same amount. The ball needs to spin to be stable. A 1/70 twist in a 10" barrel would not spin the ball enough to be stable.
Semi mentioned stripping.
I hope you're not trying to tell me that a 1:20 twist out of a 10" barrel and a 1:70 twist from a 35" barrel are spinning at the same rate! If so that is not true. When the projectile is engaged in the rifling regardless of the twist rate that ball will continue that twist rate even after it leaves the barrel.
A 1:70 twist will rotate the ball at a rate of one full turn every 70" regardless of the barrel length (10" or 32").
Could it possibly be the large difference in velocity that requires the faster twist for the pistol?