I found a LC-7-40-M16 ring sight on Ebay; and purchased it because it looked interesting and was inexpensive ($18 shipped at the time).  The LC-7-40 is designed by the same company that designed and manufactures the FN P90 reflex sights.  After receiving the sight and figuring out how it works, I began to tinker with the illumination and a way to mount it to a rifle.  The LC-7-40 is a solid piece of glass with the collimating lens, reticle pattern, and reflecting lenses ground or bonded in place.  The glass assembly is mounted inside of an aluminum housing.  The ring sight was designed to mount to a M-16 carry handle.  My 10/22s, browning auto .22, and M&P 15-22 do not have carry handles.  The simplest and cheapest solution was a Trijicon ACOG knock-off mount ($8 shipped).  I removed the M5 thread stud from the bottom of the sight and attached the sight to the ACOG mount with a countersunk M5 screw.  

Later that month I mounted the sight on one of my 10/22s and went to the range.  Using and sighting in the optic was easy.  The reticle is a thick circle, no dot or cross hair.  The eye naturally centers the target in the reticle.  Achieving 1" or smaller groups at 25 yards was easy.  We were able to hit soda cans, bowling pins, tennis balls, and a 6" self-sealing target ball out to 50 yards.

The sight uses ambient light from the target area to "illuminate" the reticle.  During certain lighting conditions the reticle would wash out.  First, I tried colored filters in front of the reticle window to create a color contrast.  The filters blocked enough light to render the reticle useless.  One day at my local hobby shop, I found fiber optic rods of varying diameters and colors.  None of them seemed bright enough or small enough to work.  Later that day I saw a display of bow sights at a local sporting goods store.  I noticed the sights had small and bright fiber optic rods.  I went home and ordered a few different strands of fiber optic replacement rods off Ebay.

The strand that works the best for my eyesight is a green .040" dia fiber optic rod.  For now, the strand is held in place with hot glue.  Now I'm on the search for a clear small diameter plastic or vinyl tube to protect the fiber optic.  After I find a tube, I will trim and reposition the fiber optic strand.  If I leave it sticking out of the sight as is, it will be damaged.

When you use the sight correctly with both eyes open, you see a bright green circle floating in space.  It is fast, accurate, and did not break the bank ($36 total).  It's not intended for hunting, home defense, or hard use.  After I finish the sight, it's going to stay on one of my range guns and occasionally see a speed steel match or two.

More info about the sight:
http://www.ds-solutions.co.uk/product_info.php?currency=USD&cPath=22_29&products_id=75
http://www.ringsights.com/Products/sights/sights.htm
http://www.ebay.com/itm/270955949792?ssPageName=STRK:MEWAX:VRI&_trksid=p3984.m1438.l2661

Pictures of the sight:










-Luke15

Creative and ingenious, congrats!
Tomac

Thanks Tomac.

I LOVE IT!!!  Nicely done sir

Color me intrigued.  I'm subscribing so I can fiddle with the links later.

A thought just occurred.  Since its not a projected dot, folks with astigmatism should be able to use it, ala the old weaver quickpoints.

Depending on bills, I might pick one up to mess around with this summer.

Would this sight be paralax free???

I have an older Colt pencil barrel AR15 with an A1 upper. This carry handle sight looks awesome. It's like 1x ACOG for $20!!! And it is made by the British company that makes the optics for FN PS90, not some cheap made in China crap. As soon as I saw this thread I ordered one instantly.

Doesn't everyone with a carry handle upper have to try one of these considering the price? How can you not? Can't wait to get mine and try it out! Thanks for the info Luke15!

This is so cool. I've got to put one together.

If only you could use a green tritium vial in addition to the fiber optic......

Very, VERY cool.

Seems like if you used a little longer fiber optic rod, you could mount the far end of it in front of your weapon light - which would illuminate the sight whenever it was turned on.

The little sight is parallax free.  It also has a tritium lamp that illuminates a secondary German style reticle (two horizontal lines and a vertical post).  But, these sights are older than the half life of the tritium.  If you notice the hole in the top of the sight; that window allows ambient light to illuminate the German style reticle in the daytime.  I am looking into ways of legally obtaining tritium vials and replace the old tritium lamp.  I have tried to illuminate the secondary reticle with fiber optics, but they were not bright enough.  It might take an LED to do the job, but that defeats the point of being battery free.

Here is good source for fluorescent fiber optics:
http://www.fiberopticproducts.com/Flourescent.htm  

I used .040", but could have used a little larger.

-Luke15

Great to know.

Even if it did have a light, a little LED light hooked to push on wouldn't be bad.  It would be great if you could get the ACET (whatever) tech for the long battery life Aimpoints have.

Have you looked into CandlePowerForums?

Looks like the smaller ones are out of stock right now.

Link

These will be gone in no time now that its been posted on arfcom. So I went ahead and ordered one for my A2 Rifle...

Thanks, OP.

Well damn.  That's pretty cool.

I ordered two of them. Going to do it similar to yours. Going to add a small battery (2032) holder on the base for an LED on top. Then I will heat the fiber optic to make a spiral gatherer on top of the battery that feeds the optic like yours. All that flat area in front of the optic is perfect for the light gathering and battery mods.

Tagged for later..

Where'd you find the mount for $8?

I think I'll grab one or two of these for an AK project!

Very interesting. Might have to snag one of these to play with. Try to coil the fiber optic somehow.

I found the base on gunbroker.

Last night I tried heating and bending the fiber optic. If the fiber optic is bent past it's natural minimum bend radius,light will bleed out of the bend.  I'm going to try bending the fiber as tight as I can without cracking it, then bond it in place.  The end glows ths brightest when ths fiber is straight, but it gets in the way and could be damaged.

Look up spot Hogg archery sights.

They and others wrap the fiber around the sight...with a little creativity one could wrap it around your forfend and add a translucent cover.

My bow sight is an armotech HD...they run they're fibrin a similar way in a smaller compact package.

Just some ideas for you all....

tag

Last night I was able to coil 2.5' of 0.040" dia fiber around a 5/8" dia rod. The coil was only 1/2" tall and the ends of the fiber were bright.  Now i'm trying to find a way to fasten the coil with mechanical fasteners or a plastic safe epoxy.

Use a piece of rod as a drum, drill its bottom and bolt to the other hole in the base.

On another note..................  Factory Paper

Great little write-up!

I've got one of these sights that I bought as sort of a novelty - but I was having trouble using it!  

I will definitely keep watching to see how this all pans out!

~Augee

Ordered a couple, they will be great for rimfires.

For $20, I had to get one to scratch my curiosity itch.  I have an ACOG compatible base sitting around to mount up to this unit.  The fiber optic looks great, especially if you get it compact enough.  What is up with the tritium location on this?  Tritium vials aren't too expensive or hard to find.  Hopefully we can just glue one in.

I like this idea.  I have a 22 w/carry handle so I'll have to try this but, I must be tired.  So, I understand you put the optic in back of the site and hot glued it in place?  How much of the optic was inserted into the sight?  Also, couldn't you heat the fiber optic a little to make it bend without hurting the illumination?  




 

Cursory internet search says that as a general rule, a fiber optic can be bent no more than 15X the cable diameter if you don't want to degrade light transmission.

Saw this and wondered if it might be made to work. Called a coil pin, used as archery sight.



BTW, the limeys selling these things on ebay owe you a percentage.....

The fiber optic is bonded to the reticle window on the front of the sight.  None of the fiber optic was inserted into the sight.  Heating fiber optic threads is not a good idea.  Heating will cause distortion to the fiber structure as well as allow the fiber to bend past the minimum radius.

Right now I am letting the 5 Minuet epoxy cure on a 1" dia fiber optic coil.  Tomorrow night or over the weekend I hope to mount it on the base of the sight, and bond the fiber to the reticle window.  I also purchased a green 6mm tritium vial off ebay.  We'll see if it makes a difference in low light.

For those that want to disassemble the sight to replace the tritium; the adjustment screws attach the prism to the housing, they are held in place by a little nut that is spot welded or silver soldered in place.

More pics of the process may be helpful.

I ordered four of the units. I have a tritium vial that has been looking for a home. Who knows, I might be able to get it to work.
also
What about using one of these FO bore lights or a much larger FO rod?

Would the larger diameter and surface area transmit more light than a .04" rod?

I read that it has a 7mm objective. Tiny compared to today's standards.

If the rod is too big in diameter, it will obstruct the objective lens.

Ok, I'm not that keen on fiber optics and what exactly you can do. I bought a sight and want to duplicate what the OP is doing. Let me see if I am getting this.

The OP is using the fiber optic rod to illuminate the reticle? OP, have you found a way to protect the fiber optic rod yet?

Also, can you just cut the fiber optic rod to the length you want?

One more thing. Does anyone know where I can get that base? I can't find one anywhere.

The base is a clone of the Trijicon factory ACOG base.  Keep an eye out for any ACOG base and pick the one that suits your budget.  You can also use the Burris AR332 base as it also uses the ACOG base.  I have seen the factory ACOG bases on the used EE boards from $15 to $50 each.

Yes, it's tiny if you're looking through the objective like it's a rifle scope, but used as it should, with 2 eyes open, I think the small objective might work out well.

Could also simply use a $.99 green LED keychain light it light it up. I like the idea of tritium though.

Below is a cross section of the sight, housing not show. Sorry for the poor quality. The doted lines are the image paths.

Eureka: Tritium fiberoptics.

http://www.hawkarchery.net/productdetails.asp?ProductID=1146399&DirectoryID=650&SupplierID=

Can you access tritium vial?

Yes, but it is not easy. The nuts that keep the adjuster screws in place are spot welded to the screws.  The weld has to be removed before the adjuster screws can be removed. Also, the prism is bonded to a plastic carrier. The carrier would have to be removed to access the tritium lamp. The tritium lamp is 1/4"x1/4"x1/8". And easy to break.

I picked one up to mess around with.

I did have an idea though.  If you are using it in a carry handle (which OP is not it appears), you could just lie the fiber optic out flat in the channel of the carry handle.  Now obviously you might want to make something to house it in, or encase it in epoxy or something, but I think it would make a nice little protected space for it to be in.  

This is probably what I will try as this is most likely going on my IDF clone type rifle.

I might be able to help you out with the tubing. PM me with dimensions you would like(I.D./O.D./wall)  and I'll check my inventory.

I got all my stuff together. It's pretty neat. Has anyone found a good way to secure the fiber optic yet? How did the tritium vials work out for ya OP?

I'm still waiting to receive my tritium.  I did make some progress with securing 18" of fiber optic to my sight.  Tomorrow I'll try to get some pictures, even though it looks like homemade sin.  18" will collect and make a lot of light in direct sun.  Almost too much light.

I also purchased one just for giggles.

The "graticule" as ring sights terms it is hard to pick up. I was going to zero it and use it in a carbine competition coming up but I think it would actually put me at a severe disadvantage over iron sights. The window is too far forward and there simply isn't breathing room to acquire the ring quickly. I wanted it to be retro and cool (which it is) but I also wanted some manner of practicality out of it as well. I thought it would be fun to compete next to the acogs and aimpoints with such a dinosaur but I think it would hurt my chances of scoring in some stages.

It is neat though and if not stressed for time or competition its a great throwback optic for casual shooting and show and tell.  

Here is my latest progress with the reflex sight and the fiber optics. The bonding job looks like homemade sin, but it works.  Given the size of the ring, I was able to shoot a 10 round 2" group at 50 yards.  That group size is all I need for our club's Ruger Rimfire style matches.  I'm faster with this sight than I am with my Aimpoint Comp M2 4 moa.  

I had similar problems that Knife_Sniper had with the sight, until I added the fiber optic.  The reticle was not bright enough and did not have enough contrast.

How did you bond it? Just with hot glue like on the sight?

3m 5 minuet epoxy. I wrapped the fiber optic around a 1" tube to bond it into the coil. Then a day later, I attached the coil to the base. I did use hot glue to attach the end of the fiber optic to the recticle lens.

ost

Are they still on eBay?  Or is my search-fu weak?