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Well, maybe not brand spankin’ new (it was announced last May) but it’s the first time we’ve seen one in the flesh.  Or in the glass and polymer, as it were.  The Meprolight M21 is a 30mm reflex sight with a selection of illuminated orange reticles.  It’s all powered by light-gathering optical fibers hidden in the face of the scope and backed up by a tritium tube with an advertised brightness half-life of 15 years. 

If you’re tired of paying through the nose for lithium CR-123 batteries, or if you’re worried the supply will dry up after the Zombie Apocalypse, Meprolight has got you covered.  (At least until the tritium dies, that is.)  With no hologram to illuminate or laser to power, the M21 doesn’t use batteries. It also has no adjustments and no moving parts except the (included) QD mount levers and the zero adjustment screws.

With no electronics and no moving parts there’s nothing much that can break, and the M21 claims to be impervious to recoil up to the .500 Beowulf and beyond.

With the 1913 rail adapter, the M21 is 4.5 inches long, 2.1 inches wide, and 2.75 inches tall and weighs 13 ounces.  It’s made to co-witness with a standard AR front sight, but it looks way more bitchin’ on a TAR-21 instead.  Suggested price is around $500, which includes a 10-year warranty and a 1913-spec QD mount.

We’re begging Meprolight for a test sample; watch this space.

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  1. “backed up by a tritium tube with an advertised brightness half-life of 15 years. ”
    How did they manage to change the half life of tritium from 12.32 years?

    • Brightness half -life is not the same as radioactive decay half life, though what the former term actually means, (Half brightness after 15 years?) and how they calculated it, is still another question.

      • The radiation causes the phosphors to give off light. If its half as radioactive, the phosphors are going to produce half as much light. After 12.32 years it could be less than half as bright due to phosphor degradation, but it can’t be more than half as bright. Right? Or is the ratio of radiation to luminescence for the phosphors not linear?

        • You are correct, matt. After 1 half-life, there will be half as many tritium atoms available to decay. Therefore, there cannot be more than half as many decays per second, and therefore not more than half as many beta particles available to dump energy into the phosphors and cause luminescence. I suspect that Meprolight thought the average gunny wouldn’t know the difference, and just rounded up to 15 years.

      • There isnt any, other than Kimber uses Meprolight night sights. its an Israeli company. Wikipedia says “Meprolight was founded in 1990 and developed its first products to meet the challenges of the Israel Defense Forces (IDF)”

  2. So let me see. Half pound of aluminum, few inches of plastic fiber optic, few hardened steel screws, one piece of glass, and a few(maybe one) vial of tritium gas.

    Totally seems worth 500$

    • Trijicon seems to feel their ACOGs, built from the same materials, are pretty valuable, so maybe there is something to it. If you want a cheap optic, there are many consumer-market imports from China that make cheap range toys.

  3. Purchased Mepro-25 some 3 years ago and has failed in the light-source (10 year warrantee for this)

    After 5 months’ of trying to contact them direct (as original seller no longer trading) finally got reply after Facebook question

    Weeks between replies to questions

    They will not honour warrantee at all

    Would not Recommended at all

    • You have to contact their US rep.

      They honor the warranty quickly and even have a program in place for replacing sights that predate the M21 or sights that are out of warranty. Kimber is no longer their rep.

      Be careful as some sellers, especially on ebay, etc., have old-stock M21s or used M21s that are old enough to be out of warranty.

  4. Revive the thread time:

    “if you’re worried the supply will dry up after the Zombie Apocalypse, Meprolight has got you covered. (At least until the tritium dies, that is.) ”

    This is not true. As long has there is an external light source* striking the fiber optic, it will light up at night.

    *flashlight, glow stick, match.

  5. The parallax is so horrible on this scope, Im wondering if you should even call it a scope. Ive got a $30 reticle with less parallax. I guess im going to need to return it

    • Do you understand how reflex sights work? First, it is not a scope. A scope is magnified and has either a fixed parallax range, or can be adjusted for parallax at any specific range. A scope requires a consistent cheek weld for a consistent eye position for accuracy.

      A reflex sight has managed parallax. Most companies advertise this as “parallax-free” but it they are not truly parallax-free, but the parallax is managed by bringing it close to the shooter, so that the parallax occurs only at ranges short enough that it does not harm accuracy, and at longer ranges, there is no parallax.

      If you look through an M21 at a wall five feet away and move your head, you will see parallax. This parallax could cause you to miss the point of aim by less than an inch at that range, probably less than the sight hight over bore will cause you to miss at that range. It makes no difference. If you aim at a target at 20 feet, you will see no parallax. Same with 200 feet.

      I have been using these optics for many years and currently have five or six of them on my rifles. I have shot with many more than that.

      • Thank you 7.62 Precision

        I was on the fence about Meprolight not because of the quality and durability mind you but how I would charge it again after 15 years. You letting me know it can be done has sold me. The cost of the unit alone will make up all the purchases of batteries in other optics.

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