If you shot at 100 and 200, I don't think you can blame a miss (by say a foot?) at 145 yds on not knowing the exact trajectory.

With "normal" ML bullets and 100 gr powder charge, and assuming your gun is zeroed at 100, the bullet would not be more than 3-4" low at 145.

For piece of mind, go ahead and shoot some at 150, but you can be assured that the drop between 100 and 145 will be about a third of the drop you see between 100 and 200.

We all miss, now and then.