A decent method for setting up a scope on a rifle is to "bore sight" it first. Well done, this startng point can put you "on paper" at 100 yards. I would start at 25 yards though. As mentioned earlier, shoot a 3 shot group. The center of this group is more or less the average of where the scope is pointed in relationship where the bore is pointed. Adjust the scope until the group is dead center of the 25 yard target. Now try at 100 yards and center. Then adjust to what ever "zero" you prefer.

As already mentioned where you "zero" should be dependent upon what distances you expect to encounter on a regular basis. For example, if you expect to be shooting no farther than 100 yards, zero it there and then double check at say 50, 150, 200.

Remember most ML loads will be clocking around 2000 fps at the muzzle while most center fire will be doing roughly 2700 or so ... soem a bit less, some a whole lot more. The muzzle velocity plus the aerodymanics of the bullet will effect the arc of the bullet's path.

In general the slower, fatter ML bullet will have a much more significant arc across an equivalent distance when compared say to a typical 30.06 Spr. medium game hunting round. So checking where the bullet hits a varuious distances is a smart thing to do.

You will often hear this rule of thumb on center fire rifles ... 2" high at 100 yards = dead on at 200 yards. That is pretty much true. There are some ballistic chart info available on the net for free. However you'll need to know the muzzle velocity to use these and some require the "ballistic coefficient" of the bullet being used.