M*CARBO Brotherhood

Tips & Tricks For S2k


thank you for your patience! this PERFECTLY addresses my issue. i don’t need ‘folding’ so i’ll get the ‘new’ factory rear, thanks again



mine doesn’t have play, so i’ll shoot it tomorrow, and see if i have any probs zeroing it. i hope not.
thanks for your thoughts on rubbing. until anyone else weighs in, i’ll attribute my concern to OCD :wink:


@500c [quote=“500c, post:227, topic:2023”]
mine doesn’t have play,

@JoeFridaySays is not talking about loose or wobble between the two halves but with the S2K folded or just before fully folded you can laterally move the two halves where as the front sight will hit sides of the rear sight butt stock pocket, I can do it with mine. It has this movement because the gun and hinge area is plastic.



Skateboard grip tape does not come rubberized, it is only granulated. If you go on Talon Grips website you can buy a 5"x7" sheet of the rubberized for $9.99 plus shipping.


dave67 & joefriday

so on the basis of this discussion (my sub2k is the gen 2 bought this month; came with the ‘old’ sight) i ordered a new sight. it arrived today. it’s another ‘old’ sight.

i just spoke with Nick at KT after being on hoooooollllddd. NIck says there is absolutely no ‘new’ sight. KT never made anything but the ‘old’ site, according to him. he says 'if anyone is getting a ‘new’ sight it must be an aftermarket sight".

guys, did i missunderstand? maybe i did and mistakenly ordered another from KT?


@500c @dave67 Giving him the benefit of the doubt, Nick is “confused” at best. You have seen photographic evidence to the contrary provided by two independent users and there are posts from multiple users noting the different sights and heights. Unless members of this Forum are suffering a collective delusion, KT unquestionably has changed the rear sight and the two sights are different in height. Have they recently severed ties with the supplier of the “new” sight and reverted to the “old” one? Anything is possible with Kel-Tec.


@500c The photos do not lie, there are two different rear S2K sights…one is shorter than MCARBO rear sight and one is the same height as MCARBO rear sight. The second photo is my rear sight that I personally put right next to my MCARBO rear sight and it is exactly the same height.


@500c You said your rear plastic sight looks like the one in the first picture correct? And the MCARBO sight is right next to it showing it is taller and you want taller correct? Does that not answer your question?


aha! MY confusion. i didn’t know that one on the right was the mcarbo…i thought it was the so called ‘revised’ KT sight, my mistake


@500c The picture on the right is NOT the MCARBO!..it is the taller plastic Kel-Tec sight which is the same height as the MCARBO aluminum sight which is to the left in the first picture.


@500c @dave67 Perhaps the labeled photo collection below will clear up any confusion once and for all and be helpful for other users in the future.

As to another point repeatedly being raised and answered, unless something is seriously out of whack with your front sight (unlikely in the vertical plane) the stock front sight post will adequately adjust to accommodate any one of these rear sights with the exception of the MCARBO Notch sight. For it, you probably will need a taller front sight post.

I am speaking from experience as to all but the notch. My statement on it is based upon reading multiple posts here and on other Forums.

One final point. The .060 (or .083) inch in added height is really minimal and you cannot rely on it to provide much relief in terms of getting up off the buffer tube. For reference, .060 inches is the same height as 15-20 pages of stacked copy paper. For any significant difference, you will need to totally replace the iron sight system with something higher or go to an optic.

Front Sight Post Upgrade

i can’t thank you enough for this issue that comes up again and again, and which has been very confusing for me and no doubt others. your ‘summary’ explanation covers all bases, and i really appreciate it


any tricks on how to get KT to send me a revised/taller factory rear? 2 calls, 1 form filled out, 1 order, no luck

call #3?


@500c No KT specific advice; just what I would do with any such call. I would ask the rep for an e-mail, send the photo I posted while on the call, explain the difference while the rep has the photo in front of them and exactly what I wanted, and ask for help.

If that isn’t practical, I would still get an e-mail address for support and then send a detailed e-mail with the photo explaining carefully exactly the same as above and concluding with a request for help and that someone call me.


ok,i just spoke w sean at KT, and again, confirming ‘nick’s’ statement, he says no such sight change was ever made. i insisted that i’d seen pictures of the two, from our forum, and he said to send them to him.

i have. stay tuned


ok, here is their not very helpful reply:


said about 2 hour(s) ago

Nick is not mistaken in this instance. It is MCarbo that sells the taller sight, not us. We only have the “factory” plastic original sight.

I asked her, in reply, if she looked at the pictures i sent, and told her that folks had actually bought new sub2k’s with the taller factory installed as the rear sight, instead of the original shorter one.

as i said, not much help. i’ll post their reply



I truly admire your persistence but think you may want to change your screen name to La Mancha – I was going to suggest Quixote, but @Goblin would never be able to spell it. Seriously though, you do realize you are investing all this time and effort in a height difference of .060 inch right? The equivalent of those 15 sheets of copy paper I mentioned? :grinning:

Since you now have some extra rear sights laying around let me suggest you try achieving a somewhat equivalent result with a larger aperture which many people prefer anyway. The MCARBO sight features a larger aperture (.170”). The OEM aperture is roughly .125 inches or 3.18 mm. I drilled mine out to 11/64 inches or .172 inches/4.37 mm; about the same as the MCARBO sight.

That is an overall difference of .047 and an effective height increase of half that or .0235 since only the radius, or upper half of the diameter difference is actually adding to the height.

So from a purely mathematical perspective, drilling an 11/64 inch aperture can get you nearly half (40%) of the equivalent of a .060 inch height increase. But that is just looking at it mathematically. From a real world and optical perspective, that larger aperture has an impact beyond its size in letting you find and center the front sight without needing to get down as far on the bolt tube. I’m sure there is a good scientific explanation way over my head, but moving a small hole higher (i.e. by increasing sight height) just doesn’t seem to give the same bang as making that hole bigger while leaving it at the same height.

And I was conservative at 11/64. You can go larger if you want. At 1/4 inch* you are on the money mathematically but as noted above that much is not really needed. Or you can make your own notch sight as previously discussed which will take you far higher than .060 inches.

Whatever you do, continued tilting at the Kel Tec windmill is looking more and more futile.

*Note that ¼ inch is just barely possible and is the diameter of the “well” on the old style sight.


@500c I haven’t kept up with the entire conversation so I wasn’t going to interrupt it in the middle but I agree with @JoeFridaySays . analysis of the mathematical perspective of the height difference regardless of any acknowledgement of by KT, or if they were even aware of the variance to begin with.
The increase in height is negligible and your still looking through the same tiny peep hole in the door.
But the improvement of the sight picture by drilling it out is where the benefit really is, whether it is the taller or shorter one. It’s like opening the door after looking through the peep hole.
This allows a larger usable sight picture area thus giving more movement within it, that still provides a suitable sight angle position as perceived by the eye.
It allows for much more possible front pin position to be at zero.
It was the first thing I did to mine after shooting it the first weekend. It’s like a whole new world and the only real improvement that can be done with the factory KT sight of either height IMO.


well, a couple of things (and i hope we’re not dominating thisi thread)…

. re this from jeffing: It allows for much more possible front pin position to be at zero. I don’t think this is right. the center IS the center in all aperture sizes

. i totally get the height discussion and the irrelevance of persuing an almost insignificant rise, however, if you go back to an earlier post, you’ll see that it was my hope to raise both front & rear about 1/4 inch, and actually move my face off the tube. i mused that noone that i can find provides a comprehensive solution to this, and speculated that joeF was onto something when he mentioned the fold-down cutout as a restriction

. i thought that IF in fact KT offered a slightly higher one (‘revised’) then anything is better than stock, since it already seemed to incorporate the larger aperture

ITMT, i’ve mounted a Red Dot on a 45deg magpul m-lok with no riser, and it just barely closes (i have the mcarbo tube cover and it impinges on that; np). now the trick is to zero it as it’s 2" higher than the bore, and 1.5 inches off center (windage). that’s a whole lot of clicks on this trs-25 (speaking of which, i have 4 of them, and it seems bushnell, sometime, unannounced, changed the MOA clicks per spec, from 1/2 MOA to 1 MOA but i cannot seem to confirm this). anyway, inspite of the various tradoffs w M-lok, this solution might work as it a/ closes, and b/ allows use of the steel. i know others throughout the forum have gone this route


@500c Forget all that for one day and trust the experience of the Forum. Drill out one of your extra sights to either 11/64 or 3/8 inches and take it to the range.

If you are still concerned about .060 inches after that and believe it is worth your time then you can continue the quest. You can even keep looking for a way to raise the entire iron sight system by a quarter inch or more which is doable but impractical if you want the gun to fold.

You have nothing to lose but a $4.50 sight and some fun at the range.

I don’t want to speak for him, but I think @Jeffing65’s point was that at distances up to 25 yards or so putting the front pin on target at any point with the aperture is probably adequate, and the larger aperture lets you do that quickly and efficiently (like a baby Ghost Ring – and in fact your eye will automatically focus in the center just as it would with a GR and that is where you will tend to place the pin). In other words, the pin doesn’t have to be at the exact center of the aperture although that obviously is best and the larger aperture lets you find it and align it on target more quickly. For long range shooting, one traditionally uses a small aperture, but you won’t be doing that and the S2K isn’t really meant for that.

Good luck with the Red Dot. A lot of users (me included) have been very happy with the TRS-25. The M-Lok rail on the S2K is plastic and has proven problematic for some so I would periodically check the connection being careful not to overtighten.

At this point, I don’t think I have anything more I can contribute on this topic.