Elevation Screw - Sinclair Speed Screw

[hoagiejoe]

I found what I believe to be the Achilles Heel of the Sinclair Speed Screw, which is on my Sinclair Competition rest. The center pin supports all the weight at the c-clip, which rests directly against the knob. It had always operated smoothly until recently. I disassembled, cleaned and regreased but now feel metal-to-metal when spinning. Perhaps there was a thin bushing between the c-clip and knob? I doubt it because there is just enough room to get the top c-clip on.

I'm looking for advise to repair/improve or alternatives. A pin with a bearing would be ideal but I don't have the machine/tools or ability to make one. I found a couple of elevation screws with fine threads but prefer the speed screw for significant elevation changes. Here is what I found:

Threads too fine (but still will consider for BR)
https://fieldandcaveoutfitters.com/...rew-free-shipping?_pos=1&_sid=735275e76&_ss=r

Wrong threads (I believe I need 1/2x20 for my Sinclair Competition rest):
http://wahlstrommachine.com/windage-rests.html

Thanks, Joe

 

[jepp2]

I'm looking for advise to repair/improve or alternatives.

Just me, but I would start by calling the Brownell's tech line.

https://www.brownells.com/shooting-...3-8-x16-threads-sku749006904-37220-70211.aspx

 

[hoagiejoe]

I spoke with Brownell's. There is no bushing, only the c-clips. My bottom clip is bent. I straightened it a bit and moved it to the top. The pin now rotates with the knob because it is somehow a tighter fit (at least with no weight on the rest). It is now smoother but I can think of a better design for the pin to secure to the knob.

 

[ridgeway]

I don't use one anymore, but what I did was made a new pin that fit close to remove slop. I use just a custom1/2-20 for elevation for LR BR.
You can always drill and tap for the 5/8-18 speed screw you posted...

 

[JFrank]

www.pacifictoolandgauge.com
Their speed screws are $39, mine works fine.....as an alternative of course
J

 

[TC260]

I need to get one, is the Pacific better than the Sinclair? Or a different one?

 

[JFrank]

I don’t believe there is any overwhelming amount of difference in functionality

 

[johara1]

I spoke with Brownell's. There is no bushing, only the c-clips. My bottom clip is bent. I straightened it a bit and moved it to the top. The pin now rotates with the knob because it is somehow a tighter fit (at least with no weight on the rest). It is now smoother but I can think of a better design for the pin to secure to the knob.

The bottom E clip does nothing but limit the travel on the internal threads, the top one holds the knob on. The outside 1/2- 20 holds it in the rest. Removed the bottom E clip for more movement and ease removal for cleaning and lubing...... jim

 

[Chuckhunter]

I replace mine with this one and I'm very pleased with it. Works quite well.

https://fieldandcaveoutfitters.com/...sion-elevation-adjustment-screw-free-shipping