If you’re looking for match ammo then like it was already suggested get a box of FGGM to start with. It’s the standard by which all match ammo is judged, I’d also recommend Hornady match and Black Hills too. Your best bet is to reload even though this is a bad time to start. I also really, really like PPU ball. It’s very accurate for ball and depending on how small of targets you are shooting at 500 it may serve you well enough not to even spend the money on match ammo. I know this won’t be popular but I discovered Wolf Military Ball to be the most accurate of ball ammo. I can get slightly less than 2 MOA out of it so it might be worth picking up a box to see how your rifle likes it. a warning on it, it’s dirty but it shoots well…