Cecil, it's no longer illegal in Texas. You do have to pay a $200 fee.
Dave:
Still illegal in Texas to make one unless you have the correct license. Plus pay the $200 fee for each one you own.
Cecil, I know how to make them too, but without good metalworking tools, the ones that you can make probably affect accuracy unless you are up close and personal.
You can search the internet to find books and "how to's" and it's legal to have the books. But don't get caught with one that isn't registered.