C-More Care and Feeding – Lenses, Diodes, and Mounts, Oh My!

This is the second post on the Care and Feeding of the C-More Sight red dot scope. If you missed the first post in the series, you might want to refer back to it for some initial comments and background. If you’re clear there, let’s dive in!

The Lens

The C-More lens is a concave piece of glass (presumably) with a thin metallic coating on the front. The coating reflects red colored light that matches the frequency of the light emitted by the diode on the scope. This is a common principle to all red dot sights. The difference with the C-More is that there’s only one lens to look through (tube scopes generally have two lenses).

The most common issue with the lens is a simple maintenance issue – you have to wipe it off. Simple, right? Use a soft cloth or towel that’s free from dirt and grit, and optionally, some glass cleaner, like Windex or similar. I’ve been known to use my shirt, if nothing else appropriate is handy. Keep the lens clean so that you can see clearly through it.

You also want to occasionally check the lens to insure that it’s secure in the ring it mounts into. If the lens starts to rotate or get loose, it needs to be repaired – it will eventually either crack or blow out entirely if left alone. Worse, if the lens is loose and moving around on every shot, your zero is moving around on every shot, too! If the gun won’t group well, the C-More lens is one thing you should check while debugging it.

The Diode

One cool feature that the C-More has that other scopes lack is the ability to change the apparent size of the dot by simply switching out the diode emitter module. C-More offers these in nominal 2, 4, 6, 8, 12, and 16 MOA sizes. Be aware that the actual observed dot size in these modules varies as a function of intensity and manufacturer’s tolerances – that is to say, you may see a slight variation over time from module to module.

Unlike a traditional tube scope, the C-More’s diode is exposed to the air (this is a side effect of the tubeless design). This leads to a couple of unique issues. The first is that, at smaller dot sizes, bright sunlight on the face of the diode may actually cause the dot to appear to be somewhat dim, or to “wash out”. Aside from insuring you have a fresh battery in the scope, there’s one accessory that might help – the LimCat Glare Shield. I run one of these on my guns. I have heard that C-More is telling some folks that report the “Wandering Windage” problem that it’s due to their glare shield, but I’ve never had an issue with mine – had them on four or five scopes, now.

The second issue is that, even with a glare shield, the face of the dot module gets dirty – the gasses from combustion of the smokeless gunpowder travels upward and balloons back around the top of the gun and collects on the face of the dot module. Other stuff gets on there, too. Eventually, you start to notice that the dot is not as bright as it used to be, and you also start to see the dot become irregular in shape – it gets non-round, or takes on a donut-like appearance (mmmm… donut…). It seems like there should be a good way to clean these things, but I’ve not heard of one that consistently works, yet. The solution, at this point, is to regard the dot module as a consumable item, especially if you run a 2, 4, or 6 MOA dot. I usually swap mine once a year or so, but definitely when I notice the dot becoming irregular, or that changing the battery still doesn’t result in an appropriate brightness level.

Speaking of brightness… When you’re shooting, you should be able to set the dot at a level where it’s bright enough that you can follow the dot completely through the recoil cycle, but not be flared out.

The Battery Cover and Battery

The C-More runs on a Duracell 1/3N or Energizer 2L76 photo battery (or equivalent). You can pay upwards of $5/each for these suckers, but there are better deals out there. I’ve used really cheap ones, and really expensive ones, and I’ve had mixed results with all of them – namely that they sometimes show up with only a partial charge. Batteries have a shelf life, so try to find them fresh, if you can. If your dot doesn’t seem to get bright enough, though, this is the first place to start. Put a fresh battery in it, and see if it gets better. In a pinch, you can stack two Energizer EPX76 batteries together – you can sometimes find the equivalent in a store that sells fishing supplies. There’s apparently a lighted bobber float that uses these batteries.

The battery is obviously consumable. I swap batteries the night before any major match, and at longer matches, I’ve swapped them mid-way through the match, too, just to insure I avoid any problems. If you like, you can keep some small zip lock baggies around to store partially used batteries for later use in practice. Don’t store more than two batteries in the same bag, though, or you’ll have a bag full of dead batteries… or possibly worse, if they line up the right way and heat up enough to cause a problem!

The only thing to really note about the battery cover is that you can over tighten the screws and crack the cover. The screws only need be to snug, not tight. The threads on the screws bite into the scope body, and hold very nicely, so you don’t need to torque them down for them to stay put.

The Mount

Every so often, it’s good to double check the screws on your mount. Just make sure they’re nice and tight. If they’re not, it’s quite possible that the mount is moving under recoil, even if only one screw is loose! Locktite those suckers, and make sure they’re tight.

If you’re using a Slide Ride style scope on an aluminum mount, don’t ignore the two screws that attach the scope to the mount in this inspection. In some ways, these are more important than the screws attaching the mount to the frame of the gun, as frequently you can retighten the mount to frame screws back up, and the gun’s zero will be maintained. Not so with the scope to mount screws!

That’s it for this installment. In the next and last one, we’ll talk about that “Wandering Windage” thing…

About the author


USPSA Grand Master, NRA Instructor, http://re-gun.com/about/

Permanent link to this article: http://re-gun.com/2011/05/c-more-care-and-feeding-lenses-diodes-and-mounts-oh-my/

5 pings

  1. DR Performance says:

    Part 2 of the C-More Care and Feeding series: http://bit.ly/iyJmdR

  2. DR Performance says:

    Part 2 of the C-More Care and Feeding series: http://bit.ly/iyJmdR

  3. xre says:

    RT @drperformance: Part 2 of the C-More Care and Feeding series: http://bit.ly/iyJmdR

  4. xre says:

    RT @drperformance: Part 2 of the C-More Care and Feeding series: http://bit.ly/iyJmdR

  5. C-More Care and Feeding – Fixing Wandering Windage | Re-Gun says:

    [...] « C-More Care and Feeding – Lenses, Diodes, and Mounts, Oh My! [...]

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