M*CARBO Brotherhood

Love my Mcarbo M Edition, but the locking pin on the M charging handle is a pain

I love my new gun, the M upgrades bring out the full potential of the platform. Well done!

However, in the interest of constructive criticism, the addition of a locking pin to the M charging handle makes reassembly quite difficult. This is a really fussy and irritating engineering solution. I understand why it was done, but why not make a new rear bolt section with a single, threaded hole to accept a threaded charging handle? No possibility of an ejected/broken/lost handle and no chance of installing the handle on the wrong side of the rear bolt. Most importantly, no fussy small part that likes spin on every axis and requires a gunsmith’s touch to orient, align and install properly.

Yes, cost is a factor, but after what I have put into this system, what’s another $40ish for a revised rear bolt that will make maintenance much easier for the life of the weapon?

Thoughts?

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I had the same beef about it and I’ve been told it works fine without that locking pin - the charging handle won’t fall out. I don’t have that charging handle - that pin business persuaded me I was better off without it - so I can’t verify this, but I trust the brothers here to tell it straight. I intend to get the charging handle when I’m not so poor.

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@phuzzy42 You are correct, I have removed the locking pin cause it is a pain to remove when break down to clean. Ever since I have put down range 75 rds. no issues or problems.

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1st time i broke mine down i had to find a long screwdriver to align properly during reassembly. Even knowing what to expect, thanks to the detailed videos.
Honestly that should be an integrated item to the front of the recoil spring assy. Im thinking about using some epoxy or shoe goo to stick it to the spring end cap.
Anyone think of a downside to that?

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If you don’t need it, why use it? Will the charging handle still pull out of the bolt with that doohickey on it? If so, I’d think MCARBO would have made it a part of the charging handle to begin with.

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Id have to look back at the video for the charging handle, but it seemed like a drop in improvement from the factory retention which only uses the plastic spring face to keep the charging handle captured.

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I’ve done almost every upgrade from mcarbo on my sub. with the exclusion of the Optics Mount because I have a different system I like better personally. the charging handle because I didn’t like the pin you have to put in. we all know the sub can get real dirty. why add another step. That’s why I use the factory charging handle

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@Stircrayzy the charging handle doesn’t fall out without it just like the original doesn’t. To me, that piece seems like a solution in search of a problem but YMMV.

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umm. It’s easy as pie.

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I couldve sworn i already replied back, but i guess i screwed that up…
The way i see it in stock form, the plastic end cap of the recoil spring is what physically retains/secures the vertical motion of the charging handle. With the steel pc, IT is retaining the handle position and the springs tension just keeps it in place. That seems like an obvious improvement to me. However, i plead ignorance to whether there was ever a “problem” that needed that solution, im still pretty new to the sub2k history.

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Your spring has a plastic end cap? (He says scratching head thinking he’s missing a part…)

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My recoil spring doesn’t have any plastic at all, it sits in the charging handle’s groove and retains it in the bolt. The reduced recoil charging handle has a groove too, along with a flat spot and a small pinhole you’re supposed to guide that piece into somehow. The brothers confirmed the piece isn’t needed, but if you want to use it, more power to you.

The original idea, if I remember correctly, was to make the reduced recoil charging handle with a shallower groove because repeated recoil might break it since it’s heavier than the stock one, and that piece was designed to keep the handle from rotating.

I don’t recall anyone here having a charging handle break, stock or heavy, though someone’s handle was slamming into the back of the cutout in the receiver. Help me out here, brothers, my memory’s not as good as it used to be.

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I got bored and took it apart to test it a little bit. I would highly recommend keeping the pin installed on the recoilless charging handle. It is there for a reason. If you take it off and not install it and you accidentally rotate the recoilless charging handle while trying to lock it back, the spring will no longer make contact with the cut out on the charging handle, which retains it, and it will be able to pull out of the bolt.

Adding pictures, you can see on the original charging handle the slot/cutout goes all the way around, and on the recoilless handle it doesn’t.

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I stand corrected, sorry for my misinformation. I was planning to get one and asked about it, and one of the brothers said it wouldn’t fall out even without that piece. I think I’ll stick with the stock handle.

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Did a quick video.

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Thanks for the visual aides @san !

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End cap was a misleading term, sorry. At the end of the spring is plastic, but is attached to the internal retaining wires. You can see in the images above.

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I feel like I might have seen a post somewhere of the heavy one breaking, but it broke at the top of the handle, where it necks down to fit in the bolt.

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If you search the threads, you will find a history of after market charging handles breaking including the Mcarbo versions. While the Company stood behind the product and provided replacements, it is still inconvenient to have it happen - and would be disastrous in a self-defense situation.

A number of innovative solutions were proposed by the Members including ideas similar to some of those expressed in this thread. Mcarbo ended up adopting the current design.

As I understand it, the weakest part of the CH is the retention cutout which in previous versions encircled the entire shaft thereby substantially reducing the cross section or overall thickness of the shaft. The new version retains more mass in the shaft by putting only a partial cut and only on one side. Since the CH theoretically could rotate and disengage, the locking pin prevents that. The pin also acts to reinforce the cutout.

All that said, I also really dislike the current design and would gladly pay for a recoil spring that had a locking pin permanently affixed to the end.

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Now THAT is a really good idea! I would buy one, too.
What do you think, Mcarbo?

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