You don't have to shoot at or near your camp necessarily including the exact elevation. If you do a little research I bet you can find a some western town nearby with some kind of community or county range. Failing that find some public land or any place you can get access to and put a box out at two hundred and check zero. It may be very slightly different than back home; for example, if you came from sea level or nearly so.
If you've done due diligence trigger work back home including ballistic programming for your load for your hunting elevation you can confirm zero at several thousand feet below hunting elev and still kill game up higher at four hundred yards.
