I have acquired and am trying to salvage a broken AR15. It went through one, possibly more hurricanes and sat in water for several months, resulting in all the steel parts rusting beyond hope. The lower, however, was in great shape once I drove out the rear pin and opened it up. Then I discovered (and later confirmed) that the original owner, when he found his rusty AR with the stuck pins, had hammered on the rear takedown pin to "try to break that sucker loose" and, because it wasn't on a proper flat surface at the time, cracked the lower's rear threaded ring that holds the receiver extension (buffer tube), and a 1/4" section at the top fell off.

I'd really like to fix this thing myself, and cheaply, just to show it could be done. And I'd rather not send it off to a gunsmith, because that would prolly cost more than a new stripped lower.

I do have a buddy who can weld aluminum. I do not have a tap or related gear to recut the threads if we weld it up.

Would it be just too "Bubba" if I welded the extension tube right onto the lower receiver?

Flame suit on:

M4M, I can relate to that. My fave "field repair" was an actual one: I swapped a new engine in by taking an axe and cutting down three saplings, and tying them together at the top to hold the winch.....

fizassist, I checked the lower receiver walls and they are still straight. One side of the remaining buffer tube ring is straight, but the other side is slightly canted ... when the time comes to do the actual rewelding I'll jig it up to square again, and with luck the weld at the top will tension it to keep it in alignment. And if you're serious about the tap loan, I'll take you up on it and of course pay shipping both ways.

Repairing this lower without surrendering it to a pro or spending hundreds in specialty tools has become one of those "matters of honor." And sometimes, it's worth so much more when you do it yourself..... Doesn't have to work forever or be a gun I'd stake my life on -- it just has to make it through a mag or two, to prove it can be done.