KAK pistol tube goes to far into the receiver

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[ARCHIVED THREAD] - KAK pistol tube goes to far into the receiver

Posted: 1/21/2015 7:27:34 PM EDT

I have a KAK pistol tube with a cheap a$$ knockoff Magpul sling adapter. The KAK does not use a castle nut and I tightened it by hand also used blue tread locker. Now my upper does not sit back far enough to get the pins in. If I back the buffer tube off a few turns the back plate is loose. Do they make a thicker end plate?

Posted: 1/21/2015 8:50:03 PM EDT

[#1]

Quoted:
.............. Now my upper does not sit back far enough to get the pins in. If I back the buffer tube off a few turns the back plate is loose. .........................

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If the upper closes on the lower and the take down pin won't go in, the issue is not with the KAK tube.

Posted: 1/21/2015 9:56:26 PM EDT

[#2]

The upper does fit fine with the buffer tube backed off a turn and loose. When you tighten the tube it seems to push the upper forward 1/16 of an inch and the pins will not go in.

Posted: 1/21/2015 10:32:27 PM EDT

[#3]

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Quoted:
The upper does fit fine with the buffer tube backed off a turn and loose. When you tighten the tube it seems to push the upper forward 1/16 of an inch and the pins will not go in.

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Tube can't push past the buffer retainer pin. Oh, so is there a buffer retainer pin in there?

- OS

Posted: 1/21/2015 11:00:00 PM EDT

[#4]

So you sure it isn't slightly over threading into the receiver, I assume it's retaining the detent? You likely need to file the upper 3/4 of the front of the tube to allow the upper to sit flush or try a different end plate as your cheap knock off is well a cheap knock off.

Posted: 1/21/2015 11:11:46 PM EDT

[#5]

Quote History

Quoted:
So you sure it isn't slightly over threading into the receiver, I assume it's retaining the detent? You likely need to file the upper 3/4 of the front of the tube to allow the upper to sit flush or try a different end plate as your cheap knock off is well a cheap knock off.

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Yes it is definitely over threaded not by much though... I'm gonna try what you said and ditch that end plate and get a decent one....thanks everyone

Posted: 1/22/2015 12:45:28 AM EDT

[#6]

I had the same problem, I ended up slightly sanding the end of the KAK tube until the upper would close on it

Posted: 1/22/2015 2:55:16 AM EDT

[#7]

Quote History

Quoted:
I had the same problem, I ended up slightly sanding the end of the KAK tube until the upper would close on it

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Ive got a different brand tube that did the same thing.

I put a peice of sandpaper on the bench and held the tube and sanded the end just enough till it would close properly.

Posted: 1/22/2015 11:59:45 AM EDT

[#8]

I don't think it's from your cheap knockoff. I think it's the tube. I have the same tube and the same problem. Thought it was the plate as well, so I tried everything from cheap $4 plates to ASAP's, Noveske QD's, and DD QD's and had the same issue. Also tried two other forged lowers. It's on my billet now. The castle nut one was a much better option.

Posted: 1/22/2015 4:11:23 PM EDT

[#9]

Quote History

Quoted:

Yes it is definitely over threaded not by much though... I'm gonna try what you said and ditch that end plate and get a decent one....thanks everyone

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Quoted:

Quoted:
So you sure it isn't slightly over threading into the receiver, I assume it's retaining the detent? You likely need to file the upper 3/4 of the front of the tube to allow the upper to sit flush or try a different end plate as your cheap knock off is well a cheap knock off.

Yes it is definitely over threaded not by much though... I'm gonna try what you said and ditch that end plate and get a decent one....thanks everyone

Or this

This is one of my favorite additions to my gun. It beats the whole castle nut and plate mess(IMHO).

Posted: 1/22/2015 6:18:02 PM EDT

[#10]

I know my KAK Gen II was a tad long when I initially set it up. When I manually pulled back on the charging handle the bolt disappeared past the rear of the ejection port, this isn't a good thing as it can cause stove pipe type of malfunctions. I simply filed a bit off the face of the KAK tube and all is well. And this isn't an just a KAK issue, I've had to do it to a number of different receiver extensions to allow the bolt the sit about 1/8" to 1/4" in front of the back edge of the ejection port as it was designed to be.

AR's maybe be easy to bolt, torque and hammer together but it doesn't mean some parts don't need to be fitted for proper operation.

Posted: 1/25/2015 1:03:23 AM EDT

[#11]

Quote History

Quoted:

Or this

This is one of my favorite additions to my gun. It beats the whole castle nut and plate mess(IMHO).

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Quote History

Quoted:

Quoted:
So you sure it isn't slightly over threading into the receiver, I assume it's retaining the detent? You likely need to file the upper 3/4 of the front of the tube to allow the upper to sit flush or try a different end plate as your cheap knock off is well a cheap knock off.

Yes it is definitely over threaded not by much though... I'm gonna try what you said and ditch that end plate and get a decent one....thanks everyone

Or this

This is one of my favorite additions to my gun. It beats the whole castle nut and plate mess(IMHO).

nice, like the ACE rifle RE gusset but for use a/ a carbine RE and inclused a QD socket that is centered. Sure, you could just use that and leave the Endplate & castle nut out. Would help w/ a LW build.