It is capable of semi-auto or 3 round burst mode. However the M4A1 and Diemaco (now Colt Canada) C8 do have a full auto fire mode, rather than the three round burst.
If you are reffering to the current US military rifle that has a burst fire capability, in the US, you cannot. Only full auto (includes burst fire) guns that were already registered with the BATFE by May 1986 can be transferred to a private citizen. The M4A1 was developed after that. You COULD get the shorter barrel of an M4 mounted to a currently registered full auto- price for a LEGAL full auto M16 series rifle is about $12,000, plus a $200 registration tax.
Only with a Prohibited Licence can you own a full auto firearm (which the M4A1 is). A semi-automatic AR-15 would require a Restricted licence.
The M4 can select semi-automatic fire or three-round bursts. The M4A1 can be switched from semi-auto to fully automatic.
The M16A1, Diemaco/Colt Canada C7, Diemaco/Colt Canada C8, and M4A1 have fully unrestricted automatic fire. The M16A2, M16A4, M16A5, and M4 are limited to a three round burst.
An M4A1 has semi and full auto capabilities, the M4 has semi and three shot burst capability, both are used by the modern U.S. Military. An M-14 is an infantry rifle used in Vietnam and Korea.
The M4A1 is a select fire weapon with full auto capabilities. Unless you owned an NFA permitted full auto lower in California prior to 1989, you won't be allowed to get one. As for AR-15 type rifles, it is possible. They must be a brand not on the CA DOJ's list of banned receivers, and they must either use a "bullet button" (thus legally making them fixed magazine rifles), or they must be featureless (no collapsible or folding buttstock, no pronounced pistol grip, no forward grip, no flash suppressor).
Perhaps they just forgot to add the "A1" to the nomenclature in CoD4. But yes, you are correct - the standard M4 carbine has the three round burst feature, while the M4A1 and the Canadian variant of the M4 (the C8) have full auto capability.
Sort of. If you're in a state which will allow you to obtain a Class III permit to own a full auto firearm, you can buy a full auto pre-1986 AR-15 lower receiver, then purchase the upper receiver and other components.
The basic M4 carbine is limited to three round bursts, but the M4A1 does indeed have unrestricted full auto capacity, as do the Canadian variants of the M4 (Diemaco [now Colt Canada] C8), and the unlicenced Chinese copy of the M4 (Norinco CQ-556A).
On full auto about 850 rounds per minute. However, the M2 was the full auto - the M1 was semi auto only, and the rate of fire was as fast as one could pull the trigger.
It has no value to a private citizen. The M4A1 was made after May 1986, and is capable of fully automatic fire. ONLY the full auto firearms already registered with the BATFE by May 1986 can be transferred to or owned by a private citizen. Since you cannot legally own it, it has no value.