Most notable features are non removable carrying handle/rear sights that have M16A1 type adjustment knobs, collapsable stock, not an LE stock like the M4's have, short barrel and doesn't have the birdcage flash hider that M16A1's have. First used 20 round box magazines, then switched over to 30 round STANAG magazines. Forward assist and shell deflector are available on this model. Front sights have a bayonet lug underneath which takes an M9 bayonet. Fire selector is non-ambidextrous and positions are Semi, Auto and Safe. M733's are not produced in burst firing configurations, as the weapon was designed as a commando carbine, which gave the weapon the name "Colt Commando".
M733's are now outdated and are replaced with M4 rifles with longer barrels, removable carrying handles and foregrips with rails on it. A weapon system similar to the M733 in terms of concept is the Navy-Seals' CQB-R(Close Quarters Battle-Rifle)weapon system, which has a short barrel like the M733 Commando.
M733 uses 5.56x45 NATO rounds like the M16s. Country of origin is USA.
The Commando in Call of Duty: Black Ops, while mostly accurate to the model available at the time, is actually an anachronistic representation of the firearm. In that time period, the flip up iron sights and rail system for mounting accessories were not available. This is likely to make allowances for customization in multiplayer, and one could speculate the fictional justification of these types of features being available to Special Operations Groups at the time.