Back in 2011 I floated a topic on Auto & Assault Carbines, at the time I was working around technical info that was exacting and screamingly pedantic and incomplete due to some of the sources being privileged information that had to be redacted or conveyed 2nd hand with omissions, the topic got away from me so I let it sit, some time later I came across a relatively simple definition for each and because of reasons I never got around to posting them, going through one of my Trav boxes I found my scribbling from back then and found the definitions and the game stats I was working on, I'll post the definitions now and get around to the game stats when I get around to deciphering my dyslexic scribbles.
Automatic Carbine: A Carbine capable of Fully-automatic Fire, it may or may not but normally is capable of Select Fire.
Assault Carbine: A Select Fire Carbine normally with a Burst Fire Limiter capability.
So M2 Auto Carbine, M4 Assault Carbine
Automatic Carbine: A Carbine capable of Fully-automatic Fire, it may or may not but normally is capable of Select Fire.
Assault Carbine: A Select Fire Carbine normally with a Burst Fire Limiter capability.
So M2 Auto Carbine, M4 Assault Carbine