Crash course in rifling and twist rate?

[Brian564]

I am trying to figure the different effects of both the number of rifling groves, and he twist rate on bullet performance, barrel life, and accuracy. That would be a massive subject, but use whatever time you have to type a little bit about it. Thanks

 

[Mikecr]

You could drop #of grooves and barrel life from rifling consideration. No notions there pass all tests.
But twist rate and accuracy are valid considerations.

The twist rate provides displacement per bullet turn. That is, 8:1 twist is 8" of displacement per turn.
Bullets are inherently unstable by design, so gyroscopic stabilization is required.
The displacement a bullet overcomes is counter to stabilization, and effective displacement(air density) is a variable. Also, there are other factors helping or hurting stabilization at any given moment.
Where stabilization is marginal, accuracy can take a hit.
Where stabilization is insufficient, bullets immediately tumble.

Everything in shooting, gun design, and your use of it, begins with a bullet.
Best to research and plan twist rate with this in mind.

 

[sable tireur]

Brian564,

Here is a little light reading on bullets in flight. There are pictures, animation and some good reading:


How do bullets fly?

Regards.