|WikiProject Firearms||(Rated Start-class)|
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"and in high velocity bullets an excessive twist can cause bullets to literally tear themselves apart under the centrifugal force"
This cannot be correct. The forward linear velocity of the projectile has nothing to do with the centrifugal force needed to keep it together as it spins. —Preceding unsigned comment added by 188.8.131.52 (talk) 19:42, 5 November 2006
Indeed excessive velocities for a given twist can make the bullet fly apart due to centrifugal force. This was a common problem with the .220 Swift if the bullet was driven too fast. The result was a blue-ish streak downrange as the bullet flew apart.
If you do some calculations, starting with a 3000 foot per second bullet in a 12 inch twist rifled barrel. You will find that in this instance, the RPM is 180,000 RPM. Three thousand feet (or revolutions) per second time 60 seconds in a minute = 180,000 RPM.
Increase the twist rate to one turn in ten inches and you can multiply the 180,000 RPM by 12/10.
Increase the velocity to 3200 feet per second and you can multiply the 180,000 RPM by 3200/3000.
It is not at all difficolt to see that the bullets may approach a quarter of a million RPM in some modern rifles.
The first time I did these calculations I thought my calculator was broken.
I'm not sure whether this has been described; according to http://www.military-quotes.com/forum/musket-barrel-rifling-t34825.html
Rifling was done by: whittling a helical guide from a log and using the wood pattern for pulling a rod or wood dowel with a piece of file on the end while shimming the cutter for each pass.
Another method used a rifling bench. It was all wood except for the hook rifler. Each pull through the bore would cut one groove. The next pull would be ratcheted over to cut the next groove. It took many cuts to get the right depth.
Perhaps mention in article ?
This is not an disambiguation page
Someone wrote: Rifling refers to helical grooves... , which is not an exact definition. We want to know what the rifling really is.
CUP may refer to many things which can be named on here, but a cup is a small, open container... Would you write: "a cup refers to a small, open container..."? I don't think so. See discussion about the subject"
184.108.40.206 (talk) 17:02, 11 July 2014 (UTC)
What causes the spin at the end?
In the german wiki regarding rifling i asked what causes the spin at the end, but i did not get an answer.Twist AS a consequence of rifling seems To be self-evident, therefore nobody is wondering. A Bullet is not formed as a screw beging forced To rotate via rifling, not At all regards erik — Preceding unsigned comment added by 220.127.116.11 (talk) 13:38, 28 March 2015 (UTC)