Several years ago while on a Quail hunt in central texas a friend of mine,who is a good shot, said he was not killing birds as he usually did.
Asking what ammo he was using , he showed me the cheap 12 ga Dove loads by WW .
I suggested a test, which I Was already familiar with ,of putting a Aluminum can at 25 -30 yds and trying his loads and my AA 1 oz loads in his Beretta auto.
The results were shocking to him as the quality loads put about twice as many pellets in the can as the promotional loads.. Try it yourself !
My first "guiding" job, going way back, was when I had the lofty title of Iowa Editor of Outdoor Life. (Not much money involved, nor much work. Just submit some short, state-specific items every month.) Anyhow, I ended up guiding some advertising guys from the magazine for Iowa pheasants--which were plentiful back then. They were all shooting 12's. One of the guys had been delegated to pick up ammo for the crew. He bought a flat of the cheapest 1 oz loads he could find. I was carrying a 16. Watched those guys blow off a lot of feathers with not a lot of birds on the ground. Sometimes I'd back them with my 16, which produced better results.
One of them remarked that I must be a really good shot (obvious confusion there!), using a 16 on pheasants when they were having trouble killing birds with 12's. I broke open my old Sauer and showed him the 1 1/8 oz high brass 6's I was shooting. Explained that it might be a case of better quality loads with more shot, along with the fact that I spent a lot of time hunting pheasants.
Not a good idea to go with el cheapo ammo when you're shooting live critters. Probably not when you're shooting targets at longer range either, but at least they don't fly off crippled.