Have you tried to buy ammo components or ammo in Mass? ...since Mitt Romney signed ammo restriction legislation into law as Mass governor this is not possible without permission and an ammo purchase license from the state.
The new NY law on ammo purchase restrictions does not specifically state that a background check is required for the purchase of powder, primers, brass, bullets and which eliminates all Internet purchases. However, the ATF classifies these items as "ammo" and, therefore, the NY legislature fully intended that the new law would apply to ammo components.
Once the NY background check system is in place, I doubt USPS, UPS, FedEx will ship hazardous materials to NY addresses (non FFLs) but we will wait and see.
In the mean time, I am hoarding in NY like crazy and, apparently, I am not alone.