If you follow the basic book, you have templates weapon, if we can call them like that. We don't care who made the knife, it is all the same stats. For firearms, the damage depend on the size of the bullets, the size clip of the category of the guns, ect... They are generic stats.
If you have Modern arms guide, you'll have a complete list of real world weapons. They add to weapons some qualities, like Dependable (Dp). A Dp weapon needs one more action die to activate critical failure.
I don't have such book, so I use the generic weapon, but I don't loose much, because the qualities will make a weapon more or less costly depending if it is a good or bad quality.