How does one adjust an old Lyman tang sight so the sight staff is held in place repeatably in a vertical position? I have turned the shaft that holds the sight staff to the base in a 360-degree circle, and it does not index anywhere. The shaft can be tightened until the sight staff is difficult to move fore and aft and resist recoil but this is not repeatable. This is a simple sight, so I must have overlooked the obvious. I will also assume that the sight staff can be indexed as the it is about useless otherwise. Thanks.

Got me. That's one for the long barreled, smokey, smelly crowd. But just off the top of my head, it should either have a leaf spring under the vertical post which engages into a flat. Or there will be a ball bearing and detente in the side.

If it's the flat spring type. The spring has either cracked or broken and fallen out. If it's the detente type it has either become frozen with polymerized oil and dirt or some one has taken it apart and the ball or spring has gone missing. Those balls and springs are made of air soluble steel and they dissolve in the air if dropped!

I stole a picture off the net. This is a Marbles sight, but it's probably a similar setup. The flat spring under the arrow is probably the culprit. I have no idea where or if you could get a replacement though. If it is, you could email Lyman direct, shedding huge crocodile tears and the big sob story of how gran-pappy used it in the squirrel uprising of 1920 and they might dig around and find one and send it to you.

MarblesTangSight13 by Rod Henrickson, on Flickr

Thanks for your suggestions. Unfortunately, the Lyman sight is not at all like the Marbles. There are neither detents nor a spring below the sight staff. I took the thing apart to blue it and nothing appears to be missing or broken. It did not index before disassembly. Why are the simplest things so hard?

When I run into something like that, I reach deep into my collection of colorful metaphors and end it with: "fawking engineers". Then I go out and buy something that works. I know it's chicken way out and much like admitting defeat, but it's much less stressful.

I'm not sure what y'all are driving at, but here's how you work a Lyman tang sight. The knurled ring on the barrel raises and lowers the sight post. Easy Peazy. The sight folds up and down freely, with no spring to prop it up in place. There are spring/thrust washers on the axle to provide tension so it doesn't flop around loosey-goosey. What locks it in position is the locking lever on the left side. This is for a Lyman #1 and #2, the most common ones.

If these simple motions aren't do-able, then there's something amiss. Without pics or a better description I don't know what else to tell you.