toad's got it. It's very easy to find somewhere to shoot 70-120 yards to get a zero/check a zero. Almost all who "zero" at 200 or 250 etc. really zero high at 100 and guess that they're zeroed for the longer range. Also, if you zero at 100 it means that your are always dialing up. If you zero at 250yds say, and you want to check you gun but you've only got a 100 yard range like most places, you either guess that your as high as you are supposed to be or you dial down.
Not a big deal either way as it's just a number, however it's very easy to find a 70-120 yard place to shoot and you are always dialing up.
