Mykeal,
The last time I ordered powder and caps from Cabellas, which was just last month, I ordered three pounds of black powder substitute that they had a sale on, and a 10 pack of Remington #10 caps. I was only charged one Hazmat fee for the entire order, they did not charge a seperate Hazmat fee for the caps and the powder.
As far as, "Getting around federal regulations regarding the shipment of explosives" is concerned. My advice is DON'T GO THERE. Play by the rules, pay the fees, beleive me these ATF guys have even less of a sense of humor than the IRS Auditors do !!! You really, really, really, DON'T want to lock horns with these guys, they play MEAN !!! Currently, you may ship, in one shipment as much as 50 lbs of Black Powder in one shipment at a time. However, there is no specified limit on how many shipments you may have comming in at any one point in time. The problem with having bulk quantites of Black Powder in your personal possession does not stem from the shipping regulations, it comes into play with storage. The ATF wants your powder stored safely, in safe explosion resistant powder storage chests, vaults, or for very large quantities bunkers. As you may surmise, most communities have regulations and limits on how much of these kinds of things may be stored in residential or combined residential/business zoned areas. In most communities, very large quantites of Black Powder, or similar explosives, cannot be stored in a residentially zoned or combined comercial/residentally zoned property. Large quantites of such items would need to be stored in some sort of submerged bunker, far, far away from neighbors and buildings, which means, a pretty big piece of land, way far out away from the city limits. Obviously, the cost of such a storage bunker would be prohibitive for a private hobyist, but not for a business, which would classify that expense as a necessary business expense.
The only legal way I know of, to "get around" these kinds of regulations regarding the shipment and storage of explosives, is, not to ship or store explosives, as such. If you buy Black Powder kits, in which, the components of the black powder are shipped out to you, not mixed, none of those components are classed as explosives by themselves. Shipping and storage of saltpeter, sulphur, charcoal, gum arabic, graphite powder, and such, unmixed, are not treated as explosives in their unmixed form.
A major pyrotechnical chemicals and kit supplier, starlight.com, does this with their flash powders, shipping them as component kits, and not mixed.
http://www.starlight.com/pyro.html
Just an FYI
ElvinWarrior... aka... David, "EW"