Just take existing similar weapons found in your weapon.sql, put them in a new notepad document, rename them, adjust their values to what is in the client value (damage wise). Rename the txt file to a .sql file, right click your database, execute batch, locate the new file extract. If its giving you errors post them here.
Take weapon xmls similar to those weapons, copy paste change, and you have custom weapons...
It really isn't that complicated, and it is doable if you are willing to learn.
There are a TON of guides here, just search...