Cannelure
A cannelure is a feature found in Metallic Cartridge ammunition in both bullets [1] and cartridge cases. [2]
In the Minie Ball |the purpose of the cannelure was two fold. For one it changed the center of gravity of the bullet so that it would turn in flight in the direction it was falling in, instead of maintaining an orientation pointing at the original line of sight from the barrel. The bullet would strike it's target by the point, instead of being slightly misaligned. [3]
The second purpose in the Minie ball and often in other bullets to be fired from black powder weapons was to hold a lubricant which would reduce the rate of bore fouling by black powder residue. [4]
In modern bullets, such as the 7.62 illustrated here, the cannelure is pressed into the circumference of the bullet to provide a strong purchase for the mouth of the cartridge case when it is crimped onto the cannelure. This is done to prevent the bullet from moving either forward of backward in the case. [4] [5]
In cartridges, the cannelure is a band pressed into the case which prevents cartridge setback. [4]
References
- ^ "cannelure". thefreedictionary.com. Retrieved 26 February 2017.
Firearms, Gunnery, Ordnance & Artillery) a groove or fluting, esp one around the cylindrical part of a bullet
- ^ "Crimping". exteriorballistics.com. Retrieved 26 February 2017.
- ^ "Barrel Twist and Bullet Stability". bisonballistics.com. Retrieved 26 February 2017.
When a statically imbalanced bullet travels down the bore, the off-center center of gravity will travel in a helical path
- ^ a b c "Handgun Cartridge Crimping". massreloading.com. Retrieved 26 February 2017.
photo of bullets with cannelures
- ^ "Cannelure". hallowellco.com. Retrieved 26 February 2017.