Use "Shoot•N•C" targets, very good luck with them out to 300 yards just looking through my scope. 400+ I use a gong target spray painted orange and just look for movement on impact. Also go to Harbor Freight. They got 20-60x spotting scopes for around $40 if I remember correctly. I've used mine for two hunting seasons and tons of shooting. Works great. Gordon is the maker.Curious, how you plan for spotting at 500 yards?
My old Tasco 20-60x is pretty useless even at 200 yards out, so I end up doing a lot of hiking to check my groups.