So whats up with the F'N Hazmat fees ?
As I understand it:
Smokeless powder is highly flammable, just like kerosene.
Primers, in quantity (not individualized like in loaded cartridges) are handled as explosives.
Use Google to look up "HazMat" or "Hazardous Materials" and "Shipping Hazmat" and wade through the regulations (you have my sympathies).
Now, understand the HazMat rules/laws have nothing to do with the fees. Complying with the regulations/laws gives the shippers something to charge us for. It does cost them some extra effort (cost) to comply.