I got the size 8 shot for dove season. I usually get the 7 should I return them or will it do the job?

8's will work just fine for doves.

Good luck returning ammo. Most people won't take it.

All I use is 8's they'll knock em down

I have used Win AA #8 for years no complaints here

That's all I've been using this year. And I have returned ammo before.

I have been shooting AA #9

7 1/2 to 9 shot are typically what you use, so you are fine, middle of the road with #8. A bigger shot (7 1/2) is better for longer range shots perhaps and wind, where as 9 shot is ideal for close range shots, and even IC chokes or bigger. So in reality, all these shots are good, just use them to your advantage depending on conditions.