I think it'll definately get you into the ballpark with a minimum amount of ammo, but I would not trust the zero without firing at least one (minimum) 3 shot group to verify the zero. If you can fire two shots, you can fire five or ten. Ammo is cheap...wasting a tag (and maybe a trip) and blowing a once-in-a-lifetime shot because you didn't shoot enough rounds to verify your zero and based your sight-in on a flyer is expensive. I can handload 20 rounds of ammo for my most expensive cartridge for about $1/round. That's less than the cost of a resident deer tag in most places.

Mike