I see referenced to rifles and then references to carbines and have never understood the difference.

Carbine usually refers to a "shortened" rifle with a barrel length of 20" or less. Frequently carbines are chambered in pistol calibers.

Google a fellow named "Carbine" Williams (David Marshall Williams) although I believe the term carbine was around long before he was born.

 

http://en.wikipedia.org/wiki/Carbine

Carbine usually refers to a "shortened" rifle with a barrel length of 20" or less. Frequently carbines are chambered in pistol calibers.

 

 

+1, this is my understanding regarding the differences between the two.

In ARs it refers to gas system length.

In ARs it refers to gas system length.

 

Not really, the carbine length gas system is called that because it came about in order to make a carbine length at from the 20" rifle.

 

Carbines are just shorter, usually lighter, versions of a rifle.