Broken Charging Handle

#279

Quick update: got the metals, the delrin, and the KT heavy bolt. Good news is all 5/16 rods fit in the hole (that’s what she said). Just need to cut the spring pocket, thread the rods and shape the delrin. But oh they joys of working, I’m booked every day except Christmas and New Year’s. Sigh, this will go on the back burner for a bit.

6061 aluminum
0-1 tool steel
718 inconel
6AL-4V titanium
1" delrin

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#280

Progress has been made, threads cut in the 6061. Boy I have no issue cutting steels but this aluminum was a PITA! Since I’m poor and don’t have dychem I used sharpie for my layout. Now just to cut the spring seat and delrin and first one is done. I really wish I had a lathe, anyone have one they want to donate lol?

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#281

Just a lil suggestion catfood, 7075 taps a lot easier than 6061 doesnt distort or chip, harder alloy, use it a lot on M/C work, and if you have a cold tank, you can actually chill harden it.not a temper you understand, but adds a toughness. CO2 is a good gas to use for that.
what does the spring seat and the delre look like schematic wise your trying to achieve?
maybe I can suggest a Macgyver way of achieving your goal.

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#282

@GOBLIN it’s basically mimmicing the stock spring seat, just not as deep. Delrin shape I’m not to sure, haven’t decided on what to do yet shape wise. Thanks for the tip on 7075, I for some unknowing reason had a senior moment and completely forgot about that aluminum. I’ll add a stick or 2 to try as well. I have a ton of co2 cartridges laying around… how does one chill 7075?

These are my miced measurements of the stock CH.

I’m still at work now on second lunch (dinner) break. I plan on using my drill press to “machine” down the seat (at home). I will not make it as deep as the stock one is. I’m thinking the 6061 is going to fail pretty quickly, seems to be very soft. Wonder how hard titanium and tool steel is to cut threads into. Anyways will give this a shot for a bit, but now it’s back to work.

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#283

nail a piece of plywood bout 8 inches wide, to a 2x4, so the 2x4 looks like a T with the plywood on top. lock the 2 X 4 in a vise make your plywood about 14" long. take your drill, lay it on its side, on the plywood, chuck facing toward the long end of the board mark 4 holes, drill, on both sides of the barrel of the drill where you marked, and install 2 heavy tywraps or hose clamps (you can add another set of holes straddling the handle to lock it as well below the trigger. ) make sure tied down and locked drill sets level or you might have to shim the thin spots till it is)
find about a 6 or 8" bastard file, with a handle. and a good set of gloves.
first my journeyman would be spinning in his grave if i told you to use a file on alloy but there is a way to do it. have a generous can of spray wd 40.
lock your alloy rod in the drill.
scribe you with lines on the sharpie.
with 6061, before you lock the rod in the drill you can use a tubing cutter to lightly scribe your lines. do not go wider stay slightly under and finish with file.

with the rod setting perpendicular to the board, start the drill . SLOWLY START removing the material as the drill spins, keeping the alloy wet with WD40. top .008 before you get to your inner diameter. and finish to size with strip of cloth back sand paper.

this is a redneck off the cuff way of doing this, BUT it is inherently dangerous. if the file shatters, or the sand strip hangs it will leave a mark.

wear eye protection.

made my cool can out of a old expired air tank(divers) machined a 3" hole in the bottom, leaving enough material for a Oring seat, cut me a 2" thick ring out of 7075, tapped thru 1 3/4 depth with a 3’ 8 pitch BT. ( Tap cost is $914.49) www.regalcuttingtools.com welded it (tig) in place over the cut seat, and then made the corresponding size threaded plug on my atlas lathe cut the bottom for a oring groove, and that part was done, added 3 other welded penetrations, one for a over pressure valve, one for a bleed off cock (SS) and the inlet for the fitting off the hose for my co2 fire extinguisher. I made a small rack for inside that reaches 6" from the bottom of the plug, hang the piece on a wire on that, close and tighten the plug, and flood the tank with co2. let it set appropriate time, before using bleed off valve to drain pressure.
keep in mind, I plugged all but the supply port and had it pressure tested before using

If you cant get your press to work form you ship it to me, and i will trim it on the atlas lathe.:+1:

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Tips & Tricks For S2k
#284

New video from Chris dropped a little while ago

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#285

@Kona I love a company that see’s an issue and come’s up with a solution, great video.

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#286

Thanks @Kona for sharing the link…you beat me to it! :sunglasses:
@Kona I’d like to send you one to see if you can break it!

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#287

@ChrisNelson no problem brother send away!

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#288

@Kona Looking forward to a full range review and the Logan torture test!:grin::+1:

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#289

Every body is missing the real fault of the charging handle.I have first hand experience with the handle. I was son the range & the handle came broke. The problem is when the handle was machined at the point of breakage it was under cut loosing over half of it’s diameter & after looking with my magnifier you could see the metal was crystallized meaning the heat treating at that point was to hard. I’m getting ready for a show this weekend when I get back I will post the pictures. Then you can see the problem. If any body is interested the show is in LaCrosse, WI there will be several Sub nuts there.

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#290

Pardon my typing it’s late you will get the drift.

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#291

I understand what your sayin. wonder how it would be made out of grade 1 titanium or 7075 alloy and chill quenched…

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#292

Thanks Chris and MCARBO. I ordered a new recoilless charging handle today. Many companies don’t listen to their customers, you guys listen and respond quickly. Kudos! Scott

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#293

@ChrisNelson

M*CARBO IS “NOT” JUST A COMPANY… WE ARE A FAMILY! @Scooter :+1:

#294

It has a high CG, the basic design is flawed…thats why they all break at the same point.

We did discuss this in detail earlier in the thread.:grin::+1:

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#295

I said I would post the pictures of my handle. You can see the the only area that has any amount of material.

DSCF0081 DSCF0080 DSCF0079

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#296

Well I installed the new recoilless charging handle with locking nut and it looks great. It is a little tricky to get the locking nut in place. I found sticking the nut to the end of the recoil spring with grease easier than using a screwdriver.

The hole for the locking nut pin is drilled all the way through the handle spindle. Whether that will be a possible weak spot remains to be seen. The hole only needs to be 1/8" deep. Of course I know nothing about manufacturing. LOL I am thinking that this is the strongest handle on the market. Check it out.

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#297

Well it finally happened, my two finger charging handle sheared off while shooting. Almost 7000 rounds before failure. I will call on Tuesday to get a replacement.

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#298

@KM55 When you receive your replacement would you please tell me if it is of the new design with that nut?

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