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Posted: 9/16/2012 7:04:17 PM EDT
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It seems as though currently 80% AR15 lowers are scarce to find, I stumbled upon a dealer selling some on GB at a decent price. I picked one up but I've found that they milled out a portion of the unit which per blueprint would normally be filled. Has anyone else run across this?
The section is milled into the rear portion of the lower but is forward of the locking pin. The section has been milled 1/2" and is centerline while per blueprint should be 7/16 and would be milled 0.031" off center. Here is the unit as received. http://imageshack.us/a/img855/1110/dsc0343qx.th.jpg Lower AR Blueprint http://imageshack.us/a/img228/4346/43043709.th.jpg Blueprint Overlayed on the picture - note the section where the material has been removed (the slot cut) near the rear. http://imageshack.us/a/img832/2774/blueprintoverlayedcopy.th.jpg Am I missing something as to why this would be done? I questioned the seller and was told that: "Thank for your concern as we have notice this and asked the ATF about it they, said that it will be ok. As it can be machined out to .500 -.004 wide x .640 depth with not problem Or you can machine per print and leave it in We have done it both way and they work fine both ways The AR10 is that way" Why would the ATF have any say in the matter of the design? I dont get it. I find it odd that someone would do the work differently (I doubt I would have purchased had I known it would be this way). But in looking at it by having this material removed it does not appear that it would affect the function of the lower? I wanted to come here and pick your brains, you guys have a wealth more experience with AR than I'll ever. Any thoughts? Sorry if I've posted this in the wrong place, I've been coming to the forums for years as I needed info but never posted until now. |
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This would be better in the DIY section, but the maker probably sent an exemplar to the tech branch and asked if it was a gun. The ATFE said no, so they're selling it as is.
You'll be removing all that metal anyway, so no, it won't have anything to do with your completed firearm. |
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Some other manufacturers of completed lowers mill that section out to 1/2" not the 7/16" like in your blueprint so it is OK like that.
It is actually prefered to have some sort of cut out like that so when you are lining up your lower to complete it you will have a reference to check to make sure it is perpendicular, parallel, square, etc. to the rest of the machining. |
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Quoted:
I've been looking for one, and haven't been able to find any in stock. This fills the bill. Pulled the pin on two of them. For anybody else looking, I think they have seven left. Dang, and I was gonna buy the ten pack. Guess I'll get a five pack and two singles. |
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