Buffer tube drilling

[Noobert]

So I have a botched 80% lower that had the buffer tower over reamed, so the threads dont engage properly. I want to jb weld it in place, and then drill 3 or 4 1/8'' holes in through the buffer tower into the extension tube, and then pin it in, and leaving room for the buffer/spring. does anyone think that once the drill goes into the extension, that would weaken the aluminum so over time, the extension flies off, weakened by the holes drilled?

[croc4]

I don't think the pins would be needed, JB weld should be enough. Although if you can fill in the buffer hole with aluminun solder and re-ream/thread it that would be better I would think....

Croc4

[Noobert]

heh, jb weld wasn't even strong enough to survive 2 hand cycles. I only need it there to be filler, not let the buffer tube move during firing. the pins will be the ones with the task of making it not shoot back

[joelukehart]

JB weld, drilling and tapping, and pinning are just band-aids. It will give you nothing but problems further down the line. I say chalk it up as a lesson learned and start over with another 80% build or buy a finished stripped lower. I don't think Stoner or Kalashnikov got it right the very first time out either.

[asheron2]

Even though they are bandaids, what do you have to lose??? Try anything to get it to work.........Is the buffer tube aluminum??? Maybe try Tig welding it on instead of using the jam nut and plate. The only problem with this is if you get the BCG stuck back youll have to drill out the back of the buffertube.

Heck if you really wanna get mean on it, clamp the buffer tube hole in a big vice and oval the hole, then true up the threads.

All of these suggestions are definately for after you have tried something better like pinning it and are just to emphasize that things can be done to get it to work again.

I definately think drilling the four holes and then tapping the buffer tube and lower is a good way to go, then you can file the extra bits of the screws that protrude into the buffertube down.

[Fjold]

You could also sleeve that tube.

Ream the hole larger than the buffer tube thread outside diameter, then make two rings (one fitting in the front and one in the rear with enough space in between to heliarc the middle seam) Clean up the inside of the hole rethread it.

[adamsreeftank]

Why don't you turn it into a 22lr pistol. That way you don't need a buffer tube at all. You can just cap it.

Then start with another blank.

[Josh3239]

I was going to post that as well. I am sure a dedicated .22LR pistol would sell quickly here if you decide you don't like it later on down the road.

[savs2k]

i say turn it into a dedicated .22 as well. You can fix it if you really want but I wouldn't half *** it. If you decided to fix it, tig weld it once the right way and be done with it.

[Noobert]

I just want a temporary full power rifle so perhaps a year or so down the line, i'll build another, so I think i'll drill it, and if it comes apart, well, thats too bad.

[ar15barrels]

So I have a botched 80% lower that had the buffer tower over reamed, so the threads dont engage properly.

What process were you using to make the hole?

[Noobert]

i did the huge drill, and even though the instructions said to run it by hand, i got tired and tried it at 150 rpm. Big mistake.

[ar15barrels]

I would open the hole up even larger, make an insert with a step and then counterbore the hole for the step.
Then you have good threads that pull against the shoulder.

Of course, this is a milling machine job for sure...

[Noobert]

yeah, no mill for me

[JagerTroop]

I was going to post that as well. I am sure a dedicated .22LR pistol would sell quickly here if you decide you don't like it later on down the road.

I agree. 22 pistol, all they way