Would Kel-tec’s tube help with reducing this idea? I was thinking about getting it but was worried the weight was too much for the purpose of the gun, being light. I just got the RCH to help with that but the thought of weight and force to these handles make sense. The skeletonized being light makes sense and there’s a video with the weight but maybe the less reports isn’t that it’s better but less popular. Least amount of +'s for it’s cost. The double finger has, double finger support and the RCH helps with recoil. The Skeletonized just looks cool really…I guess.
Are you referring to the heavy weight bolt? A number of members have installed it and report a significant reduction in recoil. You can search the term or browse the topic SUB2000 Upgrades: What Have You Installed & What’s Your Opinion? for more information but the posts could also appear under other topics dealing with recoil, butt pads, etc. It does add substantial weight to what is otherwise a light firearm. The simple and inexpensive recoil buffer “donut” sold by MCarbo also seems to help and you did not mention it.
The video I watched covered several products so I may have fast forwarded past the weight. Do you know what the weight of the SCH is?
I am also looking for an answer to that question. I would think that it’s lighter weight results in less momentum and less stress on the stem. I know a lot of us went to the RCH for recoil reduction, but the Sub2K isn’t exactly a “heavy” recoiling weapon system. If the RCH is also causing excessive wear, then maybe the SCH could be the simplest answer. Maybe we don’t have to reinvent the wheel, just get a lighter wheel.
@JoeFridaySays I pulled the weights from MCARBO and KT sites.
RCH - 3.2 oz.
2FCH - 1.6 oz.
SCH - 1.6 oz.
OEM - 1 oz.
KT heavy counterweight - 14.4 oz
I also think there is some strong possibilies in using a material that “bends and not breaks” as you suggested.
I am not so sure that members are actually getting LESS mechanical impulse just a DIFFERENT impulse. (mass x acceleration).
The Heavier bolt works well in regards to decreasing recoil in the 40cal version … I also tried it in the 9 but didn’t see a lot of difference … The 9 really doesn’t need a whole lot of recoil reduction as it’s not that bad to begin with … The buffers seem to work well in both versions as well as the heavier charging handles …
I once represented a Japanese manufacturer of chain hoists and through an interpreter was educated about the metallurgical differences in ductility and hardness and why it was critical not to place too great an emphasis on the latter when it came to practical real world strength. The whole thing about the tree that bends before the wind and all that…
Independently of my suggestion of a different material, the ability of the steel used to absorb stress and to flex instead of fracture should be considered when building a charging handle. But the instinct is to choose the hardest, strongest steel available and that is likely to be the wrong choice. Of course, I have no idea what steels actually were used or what testing was done other than the recoilless and SCH descriptions say they are made of A311 Stressproof Carbon Steel which supposedly is resistant to fatigue and stress but primarily offers the benefit of easy machinability.
EDIT: I want to emphasize that the reports of failure are relatively rare and MCarbo stands behind their products 100%. But if the S2K is going to be used as a PDW then even a low failure rate is a problem that needs to be addressed.
In regards to weight … Yes the heavier bolt adds a couple additional ounces to the gun … The trade off is in less recoil and to the ability to get back on target faster … the weight is about like adding a 12oz can of coke … weight matters if you have carry anything over any distance but you also have to look at the usefulness and effectiveness of the items you are carrying …If the gun is not giving you the desired performance, then it’s pretty much dead weight no matter what … like I stated before, I see no reason for a heavier bolt in the 9mm version, but do see a better desired results in the 40 …
Makes sense … I agree
What about a titanium - aluminum/vanadium alloy? They use it in aerospace and high end bike components. It is lighter than steel so less inertia and flexes more than steel. I think high grade stainless steel is stronger than titanium alloy but titanium alloy is stronger than many steel variants. It’s badass looking too.
@Scooter well now you fellers are into metallurgy and beyond me!
I agree that the hardest metal is not the best choice. This is true of making knife blades and often they will use a “softer” metal core to give the blade some flexibility.
As far as vanadium and titanium - I think you have to keep the cost factor and economy of scale in mind. I doubt Chris could sell enough of them to keep the costs manageable.
And I agree with @JoeFridaySays in that while McARBO stands 100% behind their parts a charging handle is simply NOT a part you want to break if you need the S2K as a PDW.
Of all the suggestions and ideas batted around I really believe @JoeFridaySays has the most practical, cost effective, fix for broken charging handles! And as he said the shape can be easily changed if it is made out of Delrin or similar material.
(Delrin already “used in charging handles for paintball guns and firearms” - I did not know that!)
Then our good friend @Kona would not have to keep buying CH by the 2-pack!
@Johnksg except you guys are working under the premise that all Keltec top of charging handle bolt knob to outer receiver are the same length. The same reason my brother can’t make a one size fits all barrel shroud because the tolerances are sloppy. Making a CH like that some would fit just fine, some would grind the CH into the receiver, and some would be too tight to fit at all.
@Kona that is the beauty of delrin type plastics: they are light weight, friction and heat tolerant, and very strong.
Since would be an MCARBO part the dimensions of the KT charging handle wouldnt matter, only the radius of the receiver tube and the diameter of the CH hole would be important.
I think we got lost in translation. I was working on the theory of an MCARBO made CH shaped to ride the receiver tube like you said JoeFridaySays posted. Where did the Keltec CH come into that? I merely referenced the top of the Keltec CH bolt knob so you would know what part I was referring to. The distance from the top of any CH bolt to the receiver is not the same. It works because the tolerances aren’t tight. You make them tight it stops working.
From here…maybe I misunderstood?
@Kona I really am excited about this! It gives us the shape and low CG out of a material that is low friction and heat resistant.
All we would need from KT is consistent receiver radius and charging handle hole diameter (pretty sure they manage that at least)
The best part is it can be manufactured for a fraction of what it costs for an MCARBO CH…why pay $29.99 when you can pay $10.99 and have a much BIGGER profit margin?
@Kona now I understand you!
Wont make a difference. You could even make the shaft slightly longer and allow the user to “trim to fit” with a simple hacksaw or low speed dremel.
Hey were did your post go?!
@johnksg I had paired the wrong pic sorry about that. Look they’re the same measurement and two separate distances between CH and receiver. My 2FCH sits closer to receiver than RCH.
@Kona just sand, file, or cut the shaft that goes into the counterweight for a tight fit.
The thick base that matches the radius of the receiver would lower your CG and would be friction resistant. (They actually make gears and bearings out of this material)
Delrin has a strength approaching aluminum with a good mass:strength:weight ratio.
MCARBO could either mould or mill a variety of shapes.
The user could use a heat gun and pliers to adjust for personal preference, such as cant, and file to their ideal.
I really think @JoeFridaySays is on to something!
The best part of Brian’s design is the wide base that is radiused to fit tightly against the receiver.
It would distribute the impact of the action cycling over a wider area, taking up some of the stress where the shaft meets the CH, with a strong semi-flexible yet still stiff material. (Kinda like outriggers on a canoe)
@ChrisNelson needs to give this one a good look! IMO