I also noticed it includes "conversion kits" as qualifying for the $2000 credit. Here's the definition:
CONVERSIONKIT.—The term ‘conversion kit’ means any part or combination of parts designed and intended for use in converting a firearm into a semiautomatic assault weapon, and any combination of parts from which a semiautomatic assault weapon can be assembled if the parts are in the possession or under the control of a person
So a pistol with a threaded barrel is an assault weapon, therefore a threading die could be used to convert a pistol into an assault weapon. Therefore a $15 die is a conversion kit worth $2000 in tax credits. Brilliant.