I like that idea!
To save a little money on purchases, I've been using ActiveJunky.com for a number of years. They offer cash-back on purchases from places like Cabela's, Brownells, Rainier Arms, Palmetto State Armory, Natchez, Academy, and a ton more. The beauty of it is it's independent of any other promo codes or sales the retailer is running so you can get a little extra savings on top of the sale price. The cash-back percentages are usually pretty small, but they can change often - I've seen Cabela's go as high as 15%! Anyway, even when it's lower, it all adds up over time.
I'll also sometimes buy discounted gift cards from Raise.com or Cardpool.com. I recently bought some ammo from Academy by buying discounted e-gift cards on Raise.com that were delivered instantly, then clicking through to Academy from ActiveJunky.com to complete my purchase - it's a layered discount approach!