I have this nice rifle I just finished building and would like to work up a target load for it. I am limited to 100 yards only, so I would guess the ladder test is out of the question (I understand it's better performed at 200 yards or more). So - what would you recommend in shooting for the smallest groups?

The way I did it for my other rifles was to select a bullet and a powder, shoot groups varying the powder by .2 grains around the min / max. Once I find the tightest group, then I begin varying the distance to the lands. This will usually give me a bullet, powder, seating dist and brass for that particular combination. At 100 yards it's not far enough to highlight any inadequacies, so is there a better method considering I'm only working at 100 yards.