Adjustable sight knob loose

[Rob W.]

I've got a carbine with T3 adjustable sight and the knob just spins free. It doesn't turn the screw to move the peep left or right. The knob can be popped on and off. Anybody know if this can be fixed or do I just need to replace the whole rear sight?

Information

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[jimb16]

Some had a pin through them and through a hole in the shaft. Check and see if yours is one of those. If it is, replace the pin. Otherwise, a bit of silver solder is in order.

[Rob W.]

Thanks Jim. No pin on this one so it look like I'll need to solder it. There is a small spring on the inside of the knob next to the shaft hole - don't see a purpose for that.

[phil441]

Rob, I'm hoping Jim is still watching this thread and will jump back in, but I think the spring you see is meant to press a small ball bearing against a bunch of indents on the sight ear to give you the click stops. If the ball bearing is missing and you can't find a suitable replacement, it might be time to start pricing a replacement sight.
Those sights weren't made to be repairable. I've never had the nerve to try to take one apart. I've had questions about some of the dimensions of the elevation ramp and have yet to find a drawing.
Good luck, and I hope Jim jumps back in to tell me I'm wrong.....
Phil

[Rob W.]

Thanks Phil, that makes sense about the ball bearing. I've got a spare sight, but hate to throw any parts away if I don't have to.

[jimb16]

Yup, the small steel ball is missing. You will need to replace that too. Look at the backof the knob. You should see the indents where the ball rides to "lock" the sight adjustment.

[phil441]

Jim, Have you ever seen an assembly drawing for the sight?
I've had no luck. Although they're not repairable, I would think that somewhere there would be a drawing showing dimensions and such.
TIA,
Phil

[jimb16]

Nope. Never saw a drawing of it. Don't know where you'ld find one either.