offthepaper,
Even though the M1 was mass-produced, that doesn't mean they all shoot exactly the same. I still think it would help help you to know how other peoples' Garands zero. In my case, using a center hold and Greek HXP:
1. The front sight is about 3/32" left from being centered.
2. 200 yard zero is almost always 8 clicks up from the bottom.
3. 100 yard zero is 2-3 clicks up from the bottom.
4. 50 yard zero is 4-5 clicks up from the bottom.
5. Other zeros correspond well with the numbers on the knob.
I have not shot this rifle at 25 yards. That said, in high-power competition, I am more consistent with this rifle than any other I own.