M*CARBO Brotherhood

Tips & Tricks For S2k


What i really like with the red dot,similar sighting system, acquisition speed and both eyes open. When I purchased my Tavor (2014) it came with a Eotech. After that there has been no going back.
At that point I had not seriously shot regularly for about 20 years. OMG what a change technology has taken!


Wow that was easy. box knife using the edges of the guides and 5 seconds later flip up rear sight.
WHen flipped forward it is elevated enough thet it is easy to re elevate and it clicks into place. SWEET. Good looking out !!

With the red dot cowitnessed with open sights you can almost use the opening of the reflex sight as a rear aperature. Of course just turn on the reflex as long as you have batteries. run out of batteries and you still have a valid accurate sight picture.


Just that easy. Had to be or it would have been beyond me. :grin:


@Wedge I have been thinking about the holosun hs510c, I have no experience with this company but I see them for $299 on Amazon and a lil cheaper on optics planet.

Looks like it comes with a QD riser?

Any issues or quirks?


That’s a decent price. I know I paid over $300 for mine. The QD mount is solid. The only “quirk” I’ve had with it is the motion activated sensor is VERY sensitive on mine. If I have it leaning on the wall and just walk by it, the optic turns on. I leave that feature off because it’s extremely easy and quick to activate when needed. Press either one of the buttons on the left side and it’s on instantly. You don’t even need to adjust the brightness.


@Wedge thats good to know. I tired out my wife’s vortex venom…without the sights is clear but needs a riser. They are competitive in price.

Never really dealt with a solar unit before…some that I have seen on the range seem like they take a moment to illuminate? Does the holosun do that?

How would it fare on a night shoot with mounted light? Any issues there?


It co-witnesses perfectly out of the box with the stock S2K front sight and MCARBO rear peep sight. I didn’t try it with the stock rear sight, but I’m sure it would be fine as there’s a good bit of adjustment range. The MCARBO rear sight is just a hair taller.

The solar aspect is totally transparent, no pun intended. It’s primarily a battery powered optic therefore it’s “instant on” like any other powered optic. The solar cell just augments the battery when there’s enough light so it takes over and doesn’t use battery. It’s also what allows for the auto-dimming feature since, obviously, it can detect ambient light levels.

I’ve never shot mine at night with a light on it, so no help there from me. Sorry! :slight_smile:


@Wedge sorry to have bombarded you with questions but I have come to value your input.

Thank you!


Oh, I did have issues with it returning to zero after re-mounting it, but that’s because of the Pic rail crossmembers on the S2K which are “peaked” at the top. Many others have reported the same thing with other types of optics, too. Once I slightly filed down affected area flat, all re-mounting zero issues went away. I just drop it on the rail, push it forward and lock it down. Very easy, quick and, most importantly, repeatable. :+1:


No problemo! That’s what this place is for. :wink:


@Wedge well I just ordered the holosun! I am running no iron sights and after my new KT thread protector gets here I can remount my muzzle brake.

I am going a similar set up as @Matt runs on his.

Should have it all finished just in time for "Shots in the Dark".


How i got mine to cowitness is using different height combinations of picatinny QD mounts.
I have a stock of 3 heights in UTG and 3 Aimpoint mounts. Witch ever one works is what I use


I think for most optics a 1/2 inch riser will give a 100% co-witness with both front and rear sights on the Sub 2000 depending on the version of the rear sight. If the rear sight is not a true co-witness, it can be replaced with a new one from Kel Tec for $4.50 plus shipping. (Kel-Tec increased the height of the rear sight at some point - probably in response to aftermarket competition).

If 1/2 inch is too low for your optic then a .83 inch riser should do the trick. Unfortunately, manufacturers are not entirely consistent in their naming conventions regarding what is a “low”, “medium” or “high” riser so you need to look at the actual height.

If you want a lower third co-witness, then use the next higher riser.


Several posters have observed the Kel Tec habit of quietly making rolling changes to the Sub 2000 without notice or documentation. In a post above, I mentioned that they had quietly changed the height of the rear sight; information I read here or in another forum and later confirmed for myself when I ordered a couple of replacement sights for some experimentation. The first photo below shows that change. If you ignore the drilled out aperture and the clipped deployment wings, the sight on the left is the “new” taller version while the one on the right is the older version.

There is a small but noticeable difference in height, but there is also a noticeable difference in quality. The older sight is better molded and finished with less flash and a nicely defined well around the aperture. See the next photo. Presumably Kel Tec changed suppliers when it changed the height.

In practical terms, if you have the older rear sight then sending Kel Tec $4.50 plus shipping for the newer version may make getting a decent sight picture a bit easier or at least loosen your molars a bit less during a day at the range.

I did not need an elevation adjustment to my front sight when I switched to the taller rear sight - perhaps because I drilled out the aperture at the same time and compensated without thinking about it in the way I sighted through the larger aperture.

Front Sight Post Upgrade
Front Sight Post Upgrade
Front Sight Post Upgrade

@JoeFridaySays Thanks for getting the info and pictures out to the Brotherhood.


No problem. Here is one other comparison photo I did when I first noted the difference in quality between the two sights. It’s a shame the newer, taller sights are not the same quality as the older ones because some parts of the design (the perimeter reinforcing rib, the height) clearly are better.


just tryiong to bumb this tread up alittle so newbies might read the good work that has been done here


Great idea. Now if I could only use that when I put it back together. I’m always amazed how far that pin will go - and never in a good direction.


Clever man you are … I’m a fan of these McGuyver solutions


Minor one … Over the years I’ve found lots of uses for sections of bicycle inner tubes. It’s strong, flexible obviously and great to use in a wedge shape to dampen noics, vibration, rubbing parts etc

I cut across the width to make some fat “rubber bands” out of it and wrapped a few around the charging handle … nice soft cushiony feel … I added enough to minimize the transition to the edges of the handle, so it’s more comfortable and meaty feeling to use.