Dizzipator
New member
Flywheel Stress
There’s one other consideration that I didn’t see mentioned, in so far as limitations on the rotation speed of the projectile.
Spin the bullet too fast and it will be torn apart when the hoop stress exceeds the tensile strength of the bullet.
An old time MIT trained mechanical engineer (Class of 57 or so) I used to work with loved this bit of trivia -
What’s the fasting rotating tool in common usage?
Rifle bullet. On the order of 240,000 RPM in high speed/small caliber bullets.
And then he would point out that bullets are limited in rotational speed by the hoop stress factoid above, which limits rotating projectile top speed simply by the needed rotation-speed-for-stability exceeding material strength if you go too fast.
It isn’t just that smooth bores aren’t slowed down by dumping energy into rifling – Spinning a properly stabilized bullet limits top rotation speed due to flywheel tress.
There’s one other consideration that I didn’t see mentioned, in so far as limitations on the rotation speed of the projectile.
Spin the bullet too fast and it will be torn apart when the hoop stress exceeds the tensile strength of the bullet.
An old time MIT trained mechanical engineer (Class of 57 or so) I used to work with loved this bit of trivia -
What’s the fasting rotating tool in common usage?
Rifle bullet. On the order of 240,000 RPM in high speed/small caliber bullets.
And then he would point out that bullets are limited in rotational speed by the hoop stress factoid above, which limits rotating projectile top speed simply by the needed rotation-speed-for-stability exceeding material strength if you go too fast.
It isn’t just that smooth bores aren’t slowed down by dumping energy into rifling – Spinning a properly stabilized bullet limits top rotation speed due to flywheel tress.