In ‘First project’, one of the things I discussed was a Williams receiver-mounted rear sight, adjustable for elevation and windage, in combination with a tall Lyman globe sight on the front.
Since writing that, I still haven’t found another receiver-mount option for the Williams, at least, not with a notched leaf. There’s plenty of peepers out there, though.
Also since writing that, I located a rear notch sight that would sit in the Ruger rear dovetail. That’s covered in ‘Version with Millet sight’.
Another thing I did was re-do the stock on my first Ruger. Part of that was mounting the Williams the ‘right’ way, with the rear leaf toward the rear of the rifle. This put the charging lever in the way of the windage adjustment knob. There was an easy fix for that: an extended charging lever.  It looks stock, but more importantly, it works well and is well-made.
Mounting the Williams the ‘right’ way did two other things.
Firstly, it moved the leaf closer to the shooting eye, which put it more out of focus. Sure, the rear sight is never in focus when you’re shooting, but it made things worse. Although not nearly as bad as a peep sight, which sits right in front of your eye and is like shooting through a foggy hole in a fuzzy donut.
Secondly, it had the functional effect of making the notch wider. That was bad. What made it even worse than that was switching the stock 18.5″ barrel for a Ruger factory ‘K’ model barrel that’s 22″ long. I used to just see the front blade in the notch. With the front blade and rear leaf so far apart (sight radius), I now saw the entire front sight sitting in the notch.
Now, the sight picture using the Millet/Desert Eagle rear sight is truly excellent. The ‘fuzz factor’ is well under control, and the front blade lines up in the rear notch in just the right proportion. So I figured, there’s only one fix for the new problems: a dovetail sight in the rear.
Since I knew the Millet option would work great, it was time to experiment. I got two more sights, both from LPA this time: another that fits the Desert Eagle  and one that fits the Browning Hi-Power Sport.  Both have 0.375 dovetails, angled at 60 degrees, but both have different heights.
Don’t do it.
On the LPA/Desert Eagle sight, the windage adjustment protrudes below the main body of the sight. This means, the elevation has to be dialed up before it can be installed. Once installed, it doesn’t adjust upward high enough to come in range of the front sight. The LPA/Browning has the same design issue, and would have to be paired with a different, and lower, front sight. It has very little range for elevation adjustment, and the elevation screw quickly gets sloppy at the upper range of elevation, so I didn’t even bother installing it to try it out.
Yet another problem: the notch in the Millet sight, which I really like, measures 0.06 wide. The notches on the two LPA sights are bigger, measuring 0.11. By comparison, the notch in the Williams receiver sight measures 0.08.
The wide notch was a problem with the Williams rear sight. The notches in the LPA sights are even wider than that.
Throw in the fact that the Millett is built to tighter tolerances and has a wider range of elevation adjustment than the LPAs, and there’s only one obvious choice. The Millet.
1. Brownells, Power Custom – Ruger 10/22 Extended Bolt Handle, http://www.brownells.com/rifle-parts/bolt-parts/bolt-charging-handles/ruger-10-22-extended-bolt-handle-prod9882.aspx
2. Precision Sales International, TRT44DE, Desert Eagle (Fits factory dovetail slot without milling), http://www.precisionsights.com/Product/trt44de.html
3. Precision Sales International, TPU60BS, Browning HP Sport, http://www.precisionsights.com/Product/tpu60bs.html