M*CARBO Brotherhood

Uh Oh... Gen 2 S2K Receiver Broke In Half


@linux_author I have an OD G17 gen2 that I bought new in November 2017. No issues yet with quite a few rounds down range.


I don’t think we’d get ignition if a case was pushed even a tenth of the rifling engagement apparent on that case.

Only real WAG I have is that the chamber would be knocked out of alignment with a springy polymer breech turning blowback into bounce forward as the bullets left the muzzle.

No way the firing pin could ignite a primer shoved that far forward and as @Johnksg has stated … the case is the piston which tries to move in the opposite direction.


—> https://www.youtube.com/watch?v=3op-C9OqhDk Kaboom Vid (short)
—> https://youtu.be/89ds4lzfdXc Kaboom Recap

This guy followed up with a video (Yesterday) unboxing the replacement S2K that KT sent with a bunch of free accessories: Light, Foregrip, Heavyweight Bolt, Buffer tube Cover, and Aluminum Fore End.
–> https://youtu.be/Pee5kT1C1gc - Unboxing of Replacement S2k

** .40 cal


That also didn’t look like a KABOOM. Just another receiver that cracked in half.


My bad… KABOOM syntax error… I didnt realize it was a technical term! :slight_smile:


A KABOOM, to me, is a gun that blows up from an overpressure situation (double charged round, barrel obstruction, etc) or fires out of battery. That’s a much more dangerous situation.


@dred a double feed could shove that casing into the barrel


Good point. That’s a strong spring with a heavy bolt/weight slamming forward.


Fixed it for me. Yep … watched that sucker for confirmation that KT was offering an aluminum forend - LMAO. I also note their fix was to send him a cerakoted black poly example.

I think KT did more than right by this guy.


I have no particular experience with this type problem, but my first guess would be that this was a out of battery discharge. A close examination of the picture of the case gives me the impression that those are not rifling marks, they are expansion marks from a unsupported discharge.

The marks go all the way through, and one (at 1:00) looks like you can see light. This is the best I can come up with.


@Spark Gotta agree with you. My 9mm has a 6 land and groove rifling. That case has 12 from what I can see. Also the rifling twist starts immediately, where those are just straight marks on the shell case.


Ok … just back from a hunt for the source of that picture. I found it at AR15.com and I feel DIRTY now.

That photo was not posted by the owner of the fubar’d Sub 2000. Rather, it was posted by a character that self-identifies as a troll. I do not think it was involved in any Sub 2000 related incident.

I’ma grab me a shower!


I’m not sure if this is possible but I don’t see why it wouldn’t be. What would happen if the barrel wasn’t fully locked and a round was chambered and fired?

The other thing I noticed is on one side of the break there is an irregular ridge down the center and the other side is a more flat surface.


Thank you @dred for getting to the bottom of this. I saw this pic on same post with pics of fubar S2K and assumed they the same!

I agree if pushed so far forward would not engage firing pin. @Kona But a double feed in an oversized chamber? Maybe. Like I said at the first I have no explanation.

@Wedge but since the S2K is hinged and the receiver is seperate from chamber/barrel that is exactly where and how would most likely break from an over pressure.

I am gonna say something is fishy. I just have never seen or heard of a case where the casing gets rifling marks down to the base, the gun blows apart, yet in one of the pics the primer isn’t even flattened!


Those breaks are too clean for a KABOOM. Pieces of plastic would have gone flying, if that were the case and I didn’t see any of that.


What am I missing here? I read the posters comments on KTOG. He stated that Kel-Tec told him their contractor for plastic parts screwed up on the formula but that it had been corrected. There was no explosion involved in this case or the others that were reported on. Question is how many more defective grip halves are there?


@Don68 my fault Don, I saw the pic of the shell with rifling marks and did not realize was a troll (thanks @Dred) and I started the discussion because I just could not figure out how such a thing can happen…it can’t!

This why I like this forum, I tend to believe folks and would never assume someone would post such a thing…I mean why?

I have come to trust the brotherhood.

WELL except @Wedge he is still suspect with me! :grin:


This article had me at KT looking at black grip replacements.
$50 for peace of mind or just wait and see what happens.


I"d wait and see what happens, especially since no one is actually getting hurt by these failures.


Yeah I think that’s the way to go, especially me having the multi mag version.
Haven’t heard of those breaking yet. It would be nice if we had a serial # range.