What does adjust up in 100 yard increments mean
Sorry, I wasn't very clear on that one. It made sense in my head, not on paper.
What I meant was: adjust your scope up in MOA for your load as if you were shooting a target every hundred yards. So up whatever your load needs at 200, 300, 400 yards. Then back down to zero, checking the measurements both directions. Then repeat.
ETA Bart is correct the farther away the measuring tape is the more accurate the test. Across the room might be difficult to see small errors. Maybe across the yard.