Agree with Bryan... but I'll add this...
I've seen "weird" 100 versus 200 yard zeros more with light weight, sporter barrels than with heavy barrels.
There are dozens of explanations as to why this happens, so brace yourself.
In my opinion, it has to do with the whipping direction of the barrel when the bullet is released from the muzzle.
Check these animations from varmint al... Barrel Harmonics Mode Shape Movies
So... the position of the muzzle at bullet release has a direct effect on where the bullet crosses the line of sight. Your scope of course looks "dead straight" at the target. Your bullet, however, must rise to cross the line of sight (since the barrel is below the scope), then begin its fall toward the zero point of the scope.
If the bullet crosses the line of sight closer to the 100 yard point, it may still be rising at the 100 yard point. The bullet is likely continuing to rise, even past the 100 yard point, then it will begin to fall... and by the 200 yard point, it's higher than you'd think it would be.
Check your 150 yard zero... we've seen seasoned long range shooters at our rifle matches who can ring the plate at 800... 900... and 1000 yards darned near every time.... but a playing card at 165 yard causes them all sorts of grief.
Most folks never plot their 165 yard zero, so they really are often surprised to find out just where it really is (ballistics drop charts don't generally agree with reality in this range)...
If you zero your rifle for a 200 yard zero (drop the scope elevation 8 clicks)... that would put your 100 yard point of impact only an inch above the crosshairs, and you'd have a "point blank range" of 275 yards, perhaps a little more. Meaning just hold right on and shoot, all the way to the extent of your point blank range.
In short, it doesn't seem that your rifle is doing anything that much out of the ordinary. I've seen far more exaggerated examples of what you're describing--which is why I offered my explanation/theory as to what's causing it.