Board Thread:General Discussion/@comment-174.93.53.97-20130826071537/@comment-10390252-20130826182850

Here's another thought: RWBY universe 'guns' don't use projectiles at all - they use Dust; specifically kinetic energy Dust. This can be fired in two distinct modes - narrow burn creates discrete, long-range energy pulses that have most of the same characteristics of  a projectile weapon. Wide burn is a less-focussed discharge and acts more like a rocket impulse. It also doesn't create a ranged destructive charge, so it can be used safely in a tight urban environment (like the street fight in episode 1) without risking bystanders being hit by shells being used for propulsion.

There is one very obvious problem with this theory - in the Red Trailer, Ruby clearly uses Crescent Rose simultaneously for propulsion and ranged attack. There are two possible ways around this:

1) Invoke Retcon and point out that the RWBY world was still in its early phases of development when the Red Trailer was written;

2) Maybe the propulsive blast is still lethal at close range for some weapons (particlarly psudo-rifles like Crescent Rose), much like a shotgun loaded with birdshot.

If you go with 2, then you have two distinct type of pseudo-projectile ammo. One, the 'rifle' shells used by Crescent Rose, that are still lethal at close range and the other, the 'shotgun' shells, used by Ember Celica, that are painful but non-lethal concussions at close range. The existence of the pistols and machine pistols used by the Red Eye Gang and Ren indicate that there are even lighter Dust payloads available in 'bullet' form but that these are not very effective against tougher targets, as Ren found out to his discomfort.