You do know that shipping isn't actually free I hope. If the companies don't charge shipping then it is already built into the price. If I were you I would just fill my shopping cart on several different web sites and see who is cheaper overall. Some companies seem to charge a ton for shipping and others don't seem to charge as much. In my experience, if you can find someone who ships USPS, it will be cheaper than UPS.
Georgia Arms has good prices and "free" shipping. Of course you're paying for shipping in the end but the last time I bought ammo (357sig, don't buy ammo anymore, handloading is waaaay cheaper) Georgia Arms was cheaper with free shipping than other places were BEFORE adding shipping. So, it was pretty darn free shipping.
I reload and buy bulk bullets from Crown Bullet (www.crownbullet.com) and they ship in a USPS Flat Rate Box for $15.00 for 70 pounds or less. I get 2000 200 grain 45 ACP bullets (68 pounds) for about $179.00 shipping included.
If you order larger quantities of ammo thefreightcharges are amortized over that amount of ammo and become more affordable. I tend to get 500 to 1000 rounds at a time and freight is low enough to offer significant savings vs. local purchases.
JWT: my experience is that the shipping (UPS) is based on the value of the product, so it goes up in proportion to the order. I'd be interested if your experience is different.
If you order larger quantities of ammo thefreightcharges are amortized over that amount of ammo and become more affordable. I tend to get 500 to 1000 rounds at a time and freight is low enough to offer significant savings vs. local purchases.
Cabela's has some good deals on ammo if you catch two of their promotions together, sale on ammo of what you want and one of their shipping promotions. Their shipping promotions are usually free or flat rate. Free is usually for orders over $X, the flat rate is usually for ordering something from a line of inventory that they have on sale(Usually seems to be clothes) and it typically applies to the entire order even if its $200 of ammo and a $5 pair of socks or something.
Sportsmans Guide also seems to frequently have free or flat rate shipping deals along with ammo sales. I've never used them however.
I believe Jack Ross ammo does flat rate shipping on large orders(They are typically backordered by a few months, quality range/plinking ammo though). Free if you're in their region(CA, NV, UT). But I'm guessing with the screen name cajun47, you're not from around here.
You can create some very nice deals for yourself at Sportsmansguide. Joining the SG Club is a given 5% (plus over $20 worth of coupons at joining), then getting the SG Visa is another 2% (pay in full every month, of course!) and they have various limited time/limited quantity deals and various coupons including free or flat rate shipping. Selection and customer service are top notch and shipping always fast in my experience. I don't understand why some "gunnies" seem to frown on them (maybe they are too big, too mainstream ).
GA Arms is great also, although they have a much smaller selection...