SR MicroSight on Williams FoolProof Sight Experience

NOTE: This idle dallying was back in 2011, so things may have changed. Further editing and fact checking... Initial mounting was to be on a 788, but I changed over to a T/C Contender, as the 788 FP needed the stock to be cut away in order to use the mounting holes.

Images to come, I have to insert them...

As always, send comments, questions, outright disbelief, whatever, to me HERE

Optical lens for rear peep (SR MicroSight - Phased Zone Plate) (original post)

Stallings Machine The Original SR MicroSight is based on a development by a high power shooter (that just happens to work at a federal research lab). David Crandall at Idaho National Laboratory.
MicroSight Approved by CMP for Service Rifle Competition
Breakthrough MicroSight Technology Improves Iron Sights
Amazing New MicroSight Technology Moves into Production (Video of MicroSight in use)

 Fly in the ointment, they have two thread sizes (for service rifle sights) of  1/4-32 or 1/4-28. Neither which will screw into the Williams Sight Aperture (7/32-40).

Oh, my. Length IS everything
OK, the old saying that length isn't everything is FALSE.

My dad was totally unable to get the Merit Target sight to work for him on his 540XR, due to bad eyesight. Went downstairs, rummaged about, pulled out my Micro-Sight, unscrewed the windage screw, took off the stock Williams aperture housing, threaded on the 1/4x32 drilled housing, and came to a full stop. The normal shank for the Micro-Sight is full threads right into the cylindrical optics housing. The Micro-Sight in the original form will not fit no-way no-how into a Williams aperture housing.

Careless measuring shows that the Williams apertures have an unthreaded shank .100" long that spaces the disc @ .030 past the edge of the windage arm. Rear end of aperture housing is @ .070" from rear edge of windage arm. Stallings Machine will not make a MicroSight housing with a .100" unthreaded shank extension.

Finally found a combination - Micro-Sight mounted in Williams FP-T/C sight

    Gods, what a nutroll, BUT it does fit. The insurmountable problem was how to screw the 1/4-32 Micro-Sight boss into an aperture housing and NOT have the exterior of the Micro-Sight housing run into the back of the Williams windage arm. This was not too difficult, BUT it took a bit of thinking, and thinking without alcohol HURTS. Start to finish, @ 1 hour. Most of that was setting up the fixture, finding the tap, and the target knobs, and figuring out how to fully seat the knobs over the ball bearings (having a 4" vice, or bigger, is good!)

    Grab yourself a Williams 5/16 "Big Game" aperture. I used my small hole gauge, and it comes out at .308-ish. Get yourself a foot of K&S Engineering #3062, 5/16 OD aluminum tubing (mics about .308-ish), with a wall thickness of .049". A 7/32 stub drill to clean up the ID. Brownells for a 1/4-32 tapered tap (yeah, aluminum likes thread forming taps, but $$$...).


Chucked the aluminum tube up in a lathe and hack sawed about .550 inch off. Chucked it onto the ER-32, (cut edge up), co-ax'd the OD of the 5/16 tubing to less than .001 off centre. drilled it out to 7/32, then tapped it to 1/4-32. NOTE: Aluminum prefers a light touch when tapping with a normal, fluted tap, so I used a "sensitive" tap wrench with the sliding arbor, not my normal spring loaded point.

7/32-40 tap went right in with no binding. Used Tap-Magic for aluminum, but any aluminum tapping fluid should do (WD-40). ER-32 chuck held tubing without slip..

    Took a file, cleaned off the flash from the hacksawing, and popped it out. Screwed the Micro-Sight into the arbor, then pushed it into the aperture, using the workbench. Added the short knobs (upgraded a non-TK version) and momentarily lost one ball bearing and the teeny spring.


Big game Apertures

Foolproof 

5D
    The Foolproof Big Game aperture sorta cramps your fingertips when using the TK elevation knob. The Big Game aperture is wider than the stock aperture, so you loose some windage. If you really need all of it, I suppose you could mill some clearance on the underside of the aperture on each side. NOTE: The Foolproof and the 5D use different attachments, FP is threaded for Windage screw, 5D has slotted ears for screws.

    The tubing snugly fits in the aperture so good it is scary. Note that the aperture has a windage mark stamped at the 6 o'clock position, this seemed to be the reason the aluminum tubing would only go in one way. Just install the aperture "backwards".

Side view.
Top view
Aperture can be used as-is.

Concerned about Light Reflections?
   Well, since it was in a ER-32 chuck, I could have pulled the threaded arbor out, turned it end for end, and drilled out the forward end to 1/4 inch. There are a number of flat black finishes which could be used to coat the inside of the arbor, reducing reflection (old timers, remember Em-New?)

    For those with a lathe, yes you can turn a stepped arbor, to go from 7/32-40 OD to 1/4-32 ID. BUT my way can be done with a fair degree of precision and IMHO, is fairly idiot proof. If one really wanted to go minimalist, you could probably use .035 walls, and skip the 7/32 tap drill. Buy a cheap collet block and a 5/16 collet.

One Possible Way to Mount

I used a Barrel band mount (.812 dia) for the front sight. I got a 3/16 Standard sight block from Steve Earle to reduce the globe sight height.... IMHO, the barrel should be d/t for a proper front sight base, but let's see if it works good.

Champion's Choice has .812 Barrel Band, but has the sight block milled on.
OK Weber has a steel barrel band. Check for .812 availability.

Contender "Bull" barrels are .810 diameter, while the various diameters for Barrel Band Sight Bases range from .750, .812, to .930 (other sizes exist as well!)