So a crime committed with a firearm is more deserving of punishment than one committed with a machete, or a bomb for that matter?
Match the punishment to the crime, not to the tool used to commit it.
Yes, it is.
Face it, its easier to kill a person with a firearm than with a machete and safer than using a bomb. A pistol is also easier to hide than a machete or most bombs, and you can kill more people with one than you could with a machete.
In the case of a bomb, there are usually plenty of other charges that go along with the bomb (its usually illegal to contruct them in the first place; owning the material is usually illegal without appropriate licenses, etc.).
Besides, murdering folks with machetes and bombs doesn't give the gun grabbers ammo for banning fire arms.