This problem almost led me to trashing this AR15 and and never touching one again.  It all started on December 25, 1990.  I received this rifle that year for Christmas and I thought it was the greatest thing in the world.  Then the first time I shot it, it had massive malfunction problems.  The buffer retainer pin kept popping out and getting jammed in the BCG and buffer tube.  

The rifle was sent back to Eagle Arms and they put a new barrel on it.

The problems continued over the years until I got old enought to start tinkering with it.  I discovered the buffer retainer pin hole was drilled too far forward.  To fix the situation, I ordered a rifle buffer tube and took it to my gunsmith firend's house.  He put the buffer tube on the lathe and took some metal off the lip so it would screw in further and hold down the buffer retainer.  Later I would file down the CAR tube that came with it to make it work.

Below are pics of the problem receiver s/n 635X.  It is not totally evident by the pics, but since the hole is drilled so far forward, it is putting stress marks on the inside of the receiver.  Hopefully, it will never break through.









Anyone ever seen something like this?

Pawn the lower off to someone in a ban state and buy a new lower. I'm sure there is someone out there that wants a iffy pre-ban.


ETA: and take the proceeds and buy you a new lower for that rifle.

I'll let you in on a little secret. You don't need the retaining pin/retaining pin spring for the weapon to function properly. Just pull them out. Now, when halving the rifle for disaseembly, be careful about that buffer and recoil spring popping out, but all in all that problem that doesn't have to stop you from shooting.

I got a Stag lower that didn't even have the hole drilled for the pin/spring. Rather than deal with returns and all that garbage, I just shoot without it. Works fine.

I should say it has been repaired and working 100% since 2001.  Since I figured out what was wrong with it I have purchased many more things AR15.

Quoted: I'll let you in on a little secret. You don't need the retaining pin/retaining pin spring for the weapon to function properly. Just pull them out. Now, when halving the rifle for disaseembly, be careful about that buffer and recoil spring popping out, but all in all that problem that doesn't have to stop you from shooting. I got a Stag lower that didn't even have the hole drilled for the pin/spring. Rather than deal with returns and all that garbage, I just shoot without it. Works fine.

That makes me feel a little better since this has a lot of sentimental value due to it being a Christmas gift from my dad.

Quoted: I got a Stag lower that didn't even have the hole drilled for the pin/spring.

If it wasn't you saying that, I wouldn't believe it.

I'm guessing it was a stripped lower when you bought it?

Hard for QC to miss that hole.

bump for the day crew.  Anyone ever seen this on an Eagle Arms before?

I've seen it on several makes.  It's easy to fix on a carbine.  Just replace the buffer tube with one that has a bit of a lip on the bottom side or modify the one you have.  It gets screwed in one more turn and you'll have no more problems.  It usually the buffer tube that is out of spec and not the lower.

Quoted: I've seen it on several makes.  It's easy to fix on a carbine.  Just replace the buffer tube with one that has a bit of a lip on the bottom side or modify the one you have.  It gets screwed in one more turn and you'll have no more problems.  It usually the buffer tube that is out of spec and not the lower.

Nope, it is 100% the lower.  I have looked at many lowers and tried many buffer tubes.  

How much out of spec do you suspect the plunger hole to be?
Just on an eyeball of my lowers and your pics, it doesn't look terribly different.
Mine are threaded all the way, and there is one turn of thread between the plunger hole and the interior of the lower.
My buffer is about 0.050" out of the lower when open.
Of course, the lower itself could be milled out differently.
Glad it's workin' for ya'.
Moon