View Full Version : thread pitch

July 4, 2010, 03:24 PM
I have a Colt national match with the elliason rear sight. There is a small nut on the windage adjusting screw that fell off after the staking failed and I need to make a new one. I was wondering if anyone knows the thread pitch of the adjusting screw as my place of work is shut down for a bit and my pitch gages are there. I can easily make the part but if anyone can help it will be appreciated.

July 4, 2010, 04:49 PM
I've forgotten. Let's figure it out. The windage is about 1 moa per click and the elevation is about 3/4 moa per click on that sight on that gun. The windage is 8 clicks per revolution. The rear surfaces of the front and rear sights are 6 11/16" (6.63875") apart. So. . .

8' = (8/60)° = 0.13333…°,

and that means,


sin(.13333…°) = 0.002327

1 / (6.6875 × 0.002327) = 64.257

So it looks like 64 TPI is likely. 2-64 is a standard UNF thread, but it certainly could be a special.