I've used AmmoSeek.com a few times when I was trying to restock my supply of .223 Remington and 9mm. At first, I was skeptical, but I found it pretty straightforward to navigate. The site gives you a good overview of prices from different sellers, which helped me find some decent deals without having to scour a bunch of different websites. I did notice that the listings can sometimes get outdated quickly, so I'd recommend checking the retailer's site directly for availability before getting your hopes up. I also encountered a couple of sellers that seemed a bit sketchy, so it's wise to stick with well-known retailers when possible. Overall, it's been a solid resource, just stay sharp and do a little homework on the sellers.