Some time ago I misplaced one of the lens covers for my Tasco 30mm Red Dot sight. I searched for a replacement and found that they are very difficult to find - or you can pay $10-15 each for upgraded replacements with flip-up and see-through features (which I don't care for).
So - I made my own using the cap from an old prescription medicine bottle.
Tools & materials:
- 70 mm x 30 mm pill bottle
- razor knife and a steady hand
- black paint
- 30 cm of paracord
- drill and bit sized same diameter as the paracord
- cigarette lighter
Step 1: Cut Carefully!
Inside the pill bottle lid are 5 small nubs that normally lock into guides on the bottle's body. Shave them off flush using the razor knife, leaving a round 38 mm inside diameter (ID) cap.
Actually you can stop here, the cap will now fit over the 38.5 mm outside diameter of the sight body.
Or - you can do a little more...
Step 2: A Little Bit of Aesthetic and Functional Improvement
I painted the cap black on the outside (not the inside as that would likely change the fit from "snug' to "impossible"!)
Then I drilled a hole in the bottle cap the same size as my paracord's diameter, inserted one end of the cord, and used a cigarette lighter to seal the end of the cord, which also effectively created a small hard plastic knot on the "inside" of the cap which prevents the cord from pulling back through.
I then did the same thing with the remaining original lens cap I still had so that the two caps are attached with about 30 cm of cord between them.
This setup serves two functions:
- Keeps the caps from getting separated
- Allows me to pull them off and leave the cord wrapped around the mounting base of the Red Dot sight where they won't get separated from the rifle and lost.