One of the biggest problems with blasters is actually written right into the description. The fact that it is a gas based weapon.
Gas, in the presence of air,
has about as much cohesive force as the story lines from Friday the
13th. It dissipates so quickly it is hard to get gas to cause an
impact at a short range, much less a long range.But suppose instead of gas we used a plasma, plasmas are affected by magnetism and thus could be held together by a strong internal magnetic force.
This idea is shot down from several different directions simultaneously. First, plasmas, while having a very high energy level, have a very low energy density. In other words, they are very hot, but there is not much there to cause destruction. This also means that it wouldn't take long for the plasma to cool down to air temperature and turn back into a gas. Once it turns back into a gas it loses its ability to be influenced by magnetism.
The one place where blasters could be an 
efficient weapon would be
in
the vacuum of space. Since there isn't any air particles to
break it up. Plus it would hold its energy for a lot longer and
would thus be able to stay plasma until it could hit the target.
efficient weapon would be
in
the vacuum of space. Since there isn't any air particles to
break it up. Plus it would hold its energy for a lot longer and
would thus be able to stay plasma until it could hit the target.In the distant future, plasma may be the weapon of choice. But for now, when you weight the energy required to create plasma and fire it off, as opposed to the energy required to fire a traditional missile; like a midget at a high-jump competition, you come up short.
Han'll have those pants down. We've gotta give him more time!
