User blog comment:Echo 1/UNSC Weaponry seems unrealistic/@comment-138261-20100715003221

Three Simple reasons why the UNSC have conventional weapons over exotic DEWS.

1. Cost: Conventional firearms are cheaper. 2. Size: Modern anti-tank LASER prototypes require most of a C-130 to power it. Considering we've only just managed to squeeze that down to infantry capable size. 3. Usefulness: Lasers are ruined by unruly weather, plasma weapons have no more anti-infantry effectiveness than conventional firearms. Less in fact. They can crispy fry you, yes, but that would require substantial impacts to actually guarantee a kill while a round would tumble through the body and cause alot more damage. Also, in terms of MAC v Plasma Weapons or other Covvie ship weapons, MACs actually produce much more damage and are much more difficult to avoid.

However, theres a much more important reason, that bungie have many times mentioned. Conventional fire arms are just so much cooler. Spraying bullets, flying brass. If the UNSC all have spouty plasma guns, there's nothing to separate them from the Covenant.