rear sight out of plumb

[Dan Cash]

I labored long with plumb lines, levels etc to get my Hoke sight plumb on my Shilo sharps. The tang seemed to be ground too much on the right side as the sight base prooved plumb on a test fixture. Finally, I crafted a period correct shim from a handy piece of beer can. Walla! the sight ran plumb and true. That was about 15 years ago and the base has not been off since. The shim does not show.

Regarding your rifle, you seem to be making quite a correction. I would suggest that you mount the rifle in a vice where you can observe a plumb line 10 feet or so away. Align the sights on the plumb line with the rifle level and the rear sight bottomed out. Secure the rifle and run the elevator up the staff while observing the alignment on the line. This will determine if the sight is out of plumb and will let you make adjustments.

Is it possible your base was shimmed before? The wind into which you were shooting may not have been as straight on as you thought, at least not all the way to the target. Is the staff bent or loose at its pivot point. Just a few things to check.
Best of Luck,
Dan