While the AR10 and AR15 are nearly identical weapons, the AR15 gets all the news

[Kaleva]

43. My proposal covers a range.

If the new caliber falls within that range, then the gun chambered to fire it would be classified as an assault weapon.

"One is often asked to define "assault weapon". Here's my definition.
Last edited Sun Jan 6, 2013, 05:09 PM - Edit history (2)

Any semi-automatic weapon that fires a rimless, semi-rimmed, or rebated rim centerfire cartridge that has a bullet of less then 6.5mm in diameter or a metal based case length of less then 50.8mm or caseless ammunition of any dimension or any rimless, semi-rimmedd or rebated Polymer-cased centerfire cartridge of any dimension.

The appearance of the gun has nothing to do with the above definition. The gun could look like a hunting rifle or it could look like something out of a Hollywood war movie. The gun could have a bayonet lug, grenade launcher, flash suppressor, pistol grip or folding stock and it might not be an assault weapon as defined by above. Or it could. It all depends on the action of the gun and the cartridge it fires.

Such a definition keeps things simple. All one has to do is first determine if the gun is a semi-automatic, see if the cartridge it is loaded with is a centerfire round and then measure the cartridge. No fuss. No muss.

If one has an issue with including semi-automatic handguns in the above, then one could refine it further by saying an assault weapon is a semi-automatic firearm that has a barrel length of 16" or longer and fires a rimless, semi-rimmed, or rebated rim centerfire cartridge that has a bullet of less then 6.5mm in diameter or a case length of less then 50.8mm.

A semi-automatic, or self-loading, firearm is a weapon that performs all steps necessary to prepare the weapon to fire again after firing—assuming cartridges remain in the weapon's feed device or magazine.

A centerfire cartridge is a cartridge with a primer located in the center of the cartridge case head.

"The rimmed cartridge is the oldest of the types and has a rim that is significantly larger in diameter than the base of the cartridge. "

"On a rimless case, the rim is the same diameter as the base of the case; it is known as an extractor groove."

"On a semi-rimmed case the rim projects slightly beyond the base of the case, though not as much as a rimmed cartridge."

"Rebated rim cartridges have a rim that is significantly smaller in diameter than the base of the case, serving only for extraction."

http://en.wikipedia.org/wiki/Rim_%28firearms%29

Rimmed cartridges do not have an extractor groove.

According to the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI), a cartridge is "a single round of ammunition consisting of the case, primer and propellant with or without one or more projectiles." Only the projectile portion is the bullet.

The case length of a 7.62x39mm cartridge is about 38.7mm



Polymer-cased ammunition (or PCA) is the concept applied to define the alternative to use polymer-based casings instead of metal-based (brass, aluminium or steel mainly) in the manufacturing of ammunition.

Caseless ammunition is a type of small arms ammunition that eliminates the cartridge case that typically holds the primer, propellant, and projectile together as a unit."