You might be able to see 30 cal holes at 800 yards with a stand up tripod sized telescope, but doubtful with a typical table top shooting range styled spotter IMO....and I'd be looking at glass that started at Swarovski prices or better. Wind vibration is going to be a problem most likely too, so the unit needs to be heavy enough to stay anchored securly.
With enough money, it'll be a peice of cake.
"These are the times that try men's soul's"...Thomas Paine
"Those who fail to learn from History are doomed to repeat it" ....Santayana
"There's a sucker born every minute" P.T. Barnum, on why he always had customers to see the sideshow features.