Broken Charging Handle


@elguapo99 thats what many users, myself included are doing. That is fine for a plinker, a game gun, but NOT so good for a personal defense weapon (PDW).

MIlled, forged, lathe cut the problems will be the same.

But if Chris Nelson starts making his own receivers it could be such a simple fix!

Imagine if the charging handle were mounted on the left side of your weapon, in front of your receiver. It could be relatively small and easy to use since you are just pulling it towards yourself!:+1:


A S2K receiver is just a pipe with some cutouts. Change the cutouts and solve several problems at once.

  1. An integrated pistol grip lower held in place by a pair of take down pins like the AR or KSG. (Trigger guard no longer a lever).

  2. The barrel and receiver held together by two more pins/screws. Instead of a folder it becomes a take down rifle.

  3. A heavy rail slotted to the receiver and mounted to the bolt group that relocates the charging handle forward and to the side. Adds mass and friction and can reduce the size of the counter weight and distribute the mass over a greater area, reducing mechanical impulse.

This would make cleaning and field stripping easy,no more broken charging handles, good ergonomics, and less recoil.

It would also make for a modular set up that MCARBO could sell “bundles” for so users could build a PCC exactly the way they want!:grin:


I like that idea but…

George Kellgren probably deserves the “Mad Swede” nickname for a lot of reasons, but I suspect he had good technical reasons other than cost for NOT putting the charging handle in this obviously preferred position. We all know it is a relatively hard and awkward pull compared to many other firearms. So I wonder what those reasons might have been. Even with my limited knowledge, I can think of a few possibilities; recoil spring length and tension required to cycle properly; blowback distance required to clear magazine, etc. Maybe most important, there is something on the inside wall of the firearm at that location. Is it the ejector? What other internals may be in the way and is it feasible to relocate them?

There are regulatory considerations to consider as well. As I understand it, the Feds inexplicably consider only the S2K bolt group to be the firearm and therefore require that it carry the serial number. This gives substantial latitude for modifying or perhaps even manufacturing and selling a replacement receiver. Moving the charging handle into the receiver would probably change that.


@JoeFridaySays excellent points and 100% correct!

Yes an MCARBO receiver would have to be serialized, you simply could not swap it out as a “part.”

as far as why George located the charging handle where he did…I do think a big factor was simplicity of manufacture and cost. He strives to bring his weapons in for some absurdly low price points, it is sort of the standard of his company.

But the big reason why it is not located forward like other blowbacks such as the Hk is that it would no longer be a folder and that is the entire marketing feature the S2K is based upon as sold by KT.

You could do it as a fixed carbine, you could even do it as a takedown rifle…but not as a folder.

However, you could split the difference and do it on the receiver such as this mod did. Not as far forward as I would like but still better than what we have!



@JoeFridaySays one other HUGE advantage an MCARBO receiver would have is to make it a larger diameter to enable AR style buttstocks and the ability to have .45 and 10mm versions.

No why George didnt do that in the first place is completely beyond me? Would have been easy to do as long as the outside diameter was the same and they adjusted the mass for the pressure of the round…one receiver, four bolt carrier choices, and an almost limitless selection of aftermarket buttstocks!


@JoeFridaySays oh and I forgot the biggest reason why he didn’t is the modular assembly method KT uses to produce firearms!

(They make all weapons on same machines in batches, no dedicated assembly lines and no specialized equipment.)

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My drawings were meant to be a piece that slides over the receiver tube and clamp on the rear of the frame halves. Thus still allowing it to fold and lock in place. But honestly it’s probably an impossible idea, but then again maybe not. Could be made out of delrin or maybe aluminum.

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@CatFood I guess I am missing something…how would it work if “clamped over the frame tube?”

A non reciprocating charging handle is interesting…not sure it would be worth the cost though. Unless you did it AR style though, but that would change the entire bolt assy.

Could you explain a bit more please?:grin:

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I’ll try to explain it a bit more, looking at the s2k from the rear. The top of this sleeve would be the same thickness as the mcarbo tube cover. The rear receiver half collar would be removed and once the kit is slid over and clamped on (tight fit on the receiver tube) thus not allowing it to be removed and clamping the receiver halves. The CH can be either left or right side mounted. A pin long enough to stick out of the receiver would replace the original CH in the bolt. The whole assemble would slide on with the bolt/bolt extension allowing use of stock butt stock. The CH would fit in a channel in the sleeve, and have a tab that has a J notch to pull back the pin in the bolt, at the rear most position in a notch and appropriate grove cut to allow CH to lock back. No spring controlling the CH. Just a detent to lock CH forward like the cz scorpion has to prevent the CH from flopping in and out while firing.

It sounds really complicated but it truly isn’t. Only spring in this would be to hold the detent for locking the CH forward. The profile looking from the rear would be like the ar stocks that have the storage pouches on both sides. This is where I wish I knew how to do CAD design. I’ll post up a few more pics in a sec.

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@CatFood so when you pull back on the J-hook it engages the charging handle and if you push it forward it disengage and will not reciprocate?

Interesting…if I understand your concept correctly! :grin:


Here is the cz scorpions CH. Edited to show approximately what it would look like. I’ll see if I can get a vid of the scorpion function.

@Johnksg there would be no stock CH, it would just be a captured pin.


@CatFood Okay now I got it! (Sorry I was a bit slow on the uptake)

The CZ CH is a very good design, a “proper shape” that is evenly distributing load and force over a much larger surface area. (The Czechs are good designers!)

A simple way you could do this is to mill out a “cut” around the counter weight that the collar fits around snugly.

You still have the problem of position, but it would do the trick! IMO

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Sweet, here is more pics of the cz and s2k.
Edit, just thought of a better easier idea lol. I’ll draw it up.


@CatFood Yep…that could do it. Similar to the rail attachment I was thinking of, although it does not bother me if CH reciprocated.

Problem I forsee is you are transitioning from a simple CNC milled/cut “pipe receiver” to more complex milled or stamped parts thus increasing the cost.

Unless…you drilled the counterweignt, inserted the shaft, and attached the charging handle to that? Then the CG would still be low, you are using a strong triangular shape, and the load and stress is being evenly distributed!

Not much meat to drill a second hole though…:confused:


@Johnksg yes it might be costly, but the reciprocating bolt is why they are breaking. Since the gen 2’s are serialized on the receiver tube a simple tube swap won’t really work. I have no idea on cnc costs or material costs but if it was around 200-300 bucks I’d go for it (fixing a known reliability issue). I’ll keep working on this, right now my microwave just electrically shorted and cought fire! Oh snap! :astonished::astonished::astonished:

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@CatFood shall I call the FD?

You have some good ideas…enjoyed batting around the concepts with you!

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@Johnksg thanks! But all is good now. That was wild! Yes it’s quite fun and keeps what is left of my mind busy. Wish I had a rapid prototype machine or a cnc machine. Hopefully I didn’t take this thread of track to much lol.

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@CatFood nope all about broken charging handles so your good brother!

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@CatFood @Johnksg

I may be showing my ignorance here, but why try to engage the existing charging handle? Why not have the new charging handle ride in a spring loaded slot alongside the bolt tube and directly engage the charging handle hole in the bolt, but in a temporary way; i.e. not permanently held in place by the recoil spring? If it also is mounted with a spring hinge then when touched by the user it will automatically slide into engagement with the bolt ready for charging. When released after charging the firearm, it (the entire piece; not just what is shown) will disengage into the position indicated in green and return to the front where it will NOT reciprocate with the bolt. I am sure there are multiple problems with this idea but maybe you guys who know firearms can take it and turn it into something workable.


@JoeFridaySays I certainly think it is a workable premise…however I am considering the cost of fabrication?

I was thinking of extending off the bolt a forward CH mounted to a rail. Simple to operate and would ride in a groove cut between the bolt and the receiver. (Would not interfere with the ejector.)

So just to make sure I am clear on Brian’s excellent diagram, you pull the charging handle out (engages bolt) pull it back, cocks weapon, and after bolt slides home push handle in to disengage?

How do you lock bolt to the rear?

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