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Posted: 2/27/2013 8:54:54 PM EDT
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I dunno if it's an upper clearance problem, or a buffer tube problem, but when I screw the buffer tube in far enough to keep the buffer retainer pin from popping out, the receiver won't seat down against the lower all of the way. If I go out a turn on the buffer tube, the buffer retainer pops out, but the receiver will seat. Add to that, the front takedown pin is hella tight, so the front pivot pin actually works back and forth as much as the detent will allow as you pivot the upper away and toward the lower. One last thing, look at the anomaly in the anodizing. Does anyone have any feedback on Aero customer service? I can assure you, that it's not a scratch from me. What a frustrating evening. The LPK went in so easy too (only my 2nd one). Any advice?
http://i19.photobucket.com/albums/b170/odaen/20130227_213723.jpg http://i19.photobucket.com/albums/b170/odaen/20130227_213806.jpg |
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Run your finger over it and you should be able to feel the lip that the buffer tube is creating from being screwed in so far.
NOW take the buffer tube back out and remove just a little bit of material from the top haolf of the tube with a file or a dremel or even a bench grinder. BUT DO NOT remove any more from the bottom half of the tube |
| Rotate the receiver extension (buffer tube) one full rotation counter-clockwise, essentially backing it out of the receiver. The buffer retainer should still seat below the buffer tube. If this is not happening, then the buffer tube is out of spec and you should take a dremel to it as the others suggested. |
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I'm confused. If the extension tube protrudes when screwed in just enough to catch the buffer retainer, isn't the LOWER out of spec, not the tube? That's what I'm thinking. The buffer retainer hole may have been drilled in the wrong place. Not necessarily. Carbine buffer tubes are not cut flush. They have extra material on the bottom half of the end of the tube to allow then to cover the buffer retainer pin without impacting the upper receiver. It is FAR more likely that the buffer tube is out of spec. |
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Quoted:
I'm confused. If the extension tube protrudes when screwed in just enough to catch the buffer retainer, isn't the LOWER out of spec, not the tube? Clearance the tube to where you can close the receivers. As you close, the carrier should push back slightly on the buffer to get it off of the retainer pin. You may even have to help by manually pushing the buffer back. If this doesn't happen, then your lower may be out of spec. Tube protrusion is a minor, end-user curable condition. The buffer thing has caused lowers to be returned or run without a buffer retainer pin. Edit: I see it has the old-style castle nut. Who is the mfr of this tube ? |
See the extra material at the bottom part of a carbine tube? This is part of the design because carbine tubes have to make an entire revolution to go to the next setting. Sometimes this means the buffer pin is barely covered, or one more revolution causes the bottom to almost strike the center part of the buffer pin. I have seen really cheap tubes old DPMS, and newer made in China) without enough extra material here and cause the issue you are seeing.
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Quoted:
Quoted:
Quoted:
I'm confused. If the extension tube protrudes when screwed in just enough to catch the buffer retainer, isn't the LOWER out of spec, not the tube? That's what I'm thinking. The buffer retainer hole may have been drilled in the wrong place. Not necessarily. Carbine buffer tubes are not cut flush. They have extra material on the bottom half of the end of the tube to allow then to cover the buffer retainer pin without impacting the upper receiver. It is FAR more likely that the buffer tube is out of spec. Good point. Thanks for pointing it out. 
My life is boring with Vltor and BCM receiver extensions. 
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| I wouldn't necessarily blame one part or the other without trying different setups. The start of the threads on the extension could be off, the buffer retainer hole could be misplaced, or the lower thread start could be causing the problem. It appears to be only off by a hair. You wouldn't expect "quality" parts to cause this but check it out on different setups first IMO. Or just grind till it fits. Good luck. |
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Quoted:
Quoted:
I'm confused. If the extension tube protrudes when screwed in just enough to catch the buffer retainer, isn't the LOWER out of spec, not the tube? Clearance the tube to where you can close the receivers. As you close, the carrier should push back slightly on the buffer to get it off of the retainer pin. You may even have to help by manually pushing the buffer back. If this doesn't happen, then your lower may be out of spec. Tube protrusion is a minor, end-user curable condition. The buffer thing has caused lowers to be returned or run without a buffer retainer pin. Edit: I see it has the old-style castle nut. Who is the mfr of this tube ? Yea, I'd like to know too. Would be nice for my retro build. Oh by the way it's screwed on backwards. Staking notches to the front.
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