Collar/Single Point Sling Mount Issue


So I did my big install yesterday, and when I was reassembling the Sub (gen 2) I went to put the single point sling mount over the collar and it doesn’t fit.

In the video Chris uses a collar with threads, but mine doesn’t have threads, just pops on. My collar appears to be bigger than the one in the video and the mount doesn’t slide over.

The product page doesn’t mention anything about different collars so I’m wondering if I’m doing something wrong?


We have recently seen a new collar design in the wild. Kel Tec did a soft update on this part. Did you get your Sub 2000 in 2018? If so, you might have the updated design. From pictures I’ve seen (look at the Generation 3 threads here), I seriously doubt the existing aftermarket sling mounts will work with your collar.


Forgot to add a picture. Yeah I bought it in 2018.

Welllllll that’s annoying. So much for my sling mount.


Yup, that’s a Gen 3. Congrats, that’s the first one I’ve seen anywhere. I wonder what else is different from a Gen 2. It would be nice if the receiver halves fit a Gen 2 because it would be a relatively cheap upgrade to Gen 3 receiver halves and a MUCH better collar nut design. $40 for both receiver halves (in basic black) plus whatever that nut cost. Oh, then another future single point sling mount from Chris/MCARBO since the one I have now wouldn’t fit. LOL

Although, if all the other MCARBO parts fit, it does sound like the receiver halves would be a direct swap. Hmmm…something to consider the next time I have to take mine apart…


Wait, what? The current Gen 2 is the one that doesn’t have threads on the receiver. Any “threads” you see are from the threaded collar nut cutting into the receiver plastic and/or left in the dried glue. There is no receiver stock threading acutally cut into the polymer by Kel-Tec. Did you have to glue yours on like we Gen 2 owners do? There was a huge thread on Facebook about the Gen 3 with the same collar you have and a Kel-Tec employee said the Gen 3s would have the back of the receiver threaded like it was on the Gen 1s. From what he said, only the Gen 2s had the crappy, cheap way of securing the collar with Locktite 380 Black Max “glue”.

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If there’s enough “meat” at the back of the receiver and that new collar nut really tightens down, he might be able to put the sling mount on first and then thread the collar nut on behind it since it has a substantially wider diameter than the smooth Gen 2 type collar nut.

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Yeah I was referring to the threads on the collar nut, sorry. Mine isn’t threaded at all, either the collar or the nut. It’s got indents that pop on to each other, you pull it on and off by hand but it isn’t really secure.


Huh, that’s weird. The Kel-Tec employee who spilled the beans on the Gen 3 earlier this year said they were going back to a threaded design like the Gen 1 had.

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the new collar nut is not really a nut, I saw the picture of the locking mechanism somewhere and it’s just a twist lock, I don’t think it’s a very good design, it seems like it would come off relatively easily.

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Yeah that’s probably it. Prior to Loctite it would kinda wiggle on there, and I just had to twist to pop it out of the grooves and pull it right off.

Wedge, I don’t think there’s much room. The actual collar is only maybe an inch or less, and the nut fits into specific indents. I’d guess the sling mount might fit over it but it wouldn’t give the nut room to fit back into place.

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Kel-Tec really needs to get their crap in one sock and make up their minds. The Gen 2 definitely has a threaded collar nut (probably left over from the Gen 1), but the receiver halves are NOT threaded. :roll_eyes:

There’s no denying that George and their engineering department are quite :crazy_face: sometimes. From the sound of it, it looks like you might be needing to glue yours in the future, too.

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Understood. I made that post when I still thought it was a threaded on design, per the Kel-Tec employee. :+1:

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yea, I do understand that you don’t want to thread polymer when the nut is metal but they could have spent the extra few cents to line the back end with a bit of metal so we don’t have to constantly glue and un-glue our firearms, kinda feel like it’s a toy when I have to put glue on a firearm…

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Even still with the Locktite glue, threads in the polymer would make the whole lockup much more secure and the collar nuts wouldn’t just pop off/loose like they do now. They’d have to unthread all the way, which would most likely never happen, especially when using a recoil tube cover. And, it’s not like you have to crank down on the collar nuts, either. Threading in the receiver polymer would make that even less so.


Maybe the actual Gen 3 will be, and this was just a prototype? I’ve had it since…May? Ordered online so no telling how long it was in a warehouse. It’s fine I guess, but wish I’d realized it wasn’t compatible with the sling mount. Anyone want to buy it? :joy:


I’d sure as hell hope they aren’t selling “prototypes” to the general public. Then again, some would say all Kel-Tec designs are basically prototypes anyway. :rofl:


From what I’ve seen they seem to fall somewhere between drunk rednecks and mad scientists (which, of course, I mean as a compliment).

Can’t say I’ve noticed anything else different from other Gen 2’s though, so not sure what the deal is. Everything else MCARBO fit just fine.


Seems like that’s true, even with the Gen 1s at least as the internals go. I don’t recall any Gen 1/Gen 2 specific internal parts from MCARBO, so if they fit in a Gen 3, same same. But, thanks for providing that info. Sounds like it would do zero good to “upgrade” a Gen 2’s receiver halves and collar nut to the Gen 3 design. If anything, for me, it would be a downgrade since I’d no longer be able to use my MCARBO sling mount.


Wedge, I disagree. Kel Tec is selling Gen 2s. That collar is just a rolling update to the Gen 2 design. Please don’t start the confusion that will never get sorted. Until Kel Tec announces and then releases a Generation 3, we have Sub 9s, Gen 1s or Gen 2s.


It’s more than that with an updated design at the back of the receiver where that collar nut mates, too. But, whatever…