AR15 A2 stock assembly question

[ny32182]

I am in the process of putting together a 20" AR with an A2 stock, and have a question.

I would like to get the lower refinished. If I do and it is disassembled, is there any staking that is going to be undone like there is on a carbine castle nut/endplate? I'm just not that familiar with how the A2 receiver extension and stock go together. Is there any staking called for in milspec assembly of of the A2 stock?

 

[Onmilo]

No staking on the extension tube, it is a crush fit only.
There is a stud on the buttstock that fits a depression on the receiver that prevents the extension tube from unscrewing with the stock in place.

 

[ny32182]

Ok; so anyone who can take it apart will be able to put it back together properly?

 

[Onmilo]

I am a bit confused here.
You say you are putting a kit together but it needs to be refinished?

Are you using a pre assembled lower?

In theory the extension tube should be fairly easy to remove from the lower receiver.
I use a lower receiver action block to secure the lower in a vise, my left hand to steady the receiver and a 10" Cresent wrench to remove the extension tube.

I have encountered tubes glued to the receiver with everything from JB Weld to red LocTite and these present a challenge.

Remember when the tube pops loose from the receiver to place your left hand over the buffer tube retainer pin/spring assembly in the bottom of the threaded area so they don't go sailing into the sunset when the extension tube screws out free enough to release this little assembly.

 

[ny32182]

What I did was buy a complete A2-stocked lower and a complete upper, but from two different makes. The shades of the finish don't match as well as I would like, so I would like to get the lower refinished.

What I'm worried about, is that on a carbine castle nut/endplate, there is (or should be) a staking job so that the castle nut doesn't come loose. The staking marks are circled in this picture:



Unfortunately I'm not as familiar with how the A2 stock goes together, and I'm just wondering if there is any similar staking that will need to be undone to take apart the lower, and then redone when it goes back together.

 

[TexasRifleman]

there is (or should be) a staking job so that the castle nut doesn't come loose.

No there should NOT be. Who put that lower together?

I've never seen a staking job on that on any lower I've ever bought, and never used one on any I've built.

Who made the lower?

 

[ny32182]

No there should NOT be. Who put that lower together?

I've never seen a staking job on that on any lower I've ever bought, and never used one on any I've built.

Who made the lower?

Yes there should be; the lower was made by LMT and the staking is mil-spec.

I'm just curious if there is any staking called for in a properly assembled A2 stocked lower.

EDIT: maybe there is some confusion about the picture. The picture is of the proper staking job on a receiver with a *carbine* extension. My quesion is regarding a lower with a full length A2 extension, and whether a similar staking should be present.

 

[TexasRifleman]

and the staking is mil-spec.

Interesting.

Neither of my (factory built) Bushmasters have any staking.

Odd.

 

[DMK]

No staking. You put the buffer retaining pin and spring in. Holding them down, you screw the buffer tube in until it stops. You install the detent and spring for the rear assembly pin. Put the A2 spacer on the end of the buffer tube. Put stock shell over buffer tube. Install the buttplate and screw. Put some locktite on the screw. That's it.

 

[ny32182]

Neither of my (factory built) Bushmasters have any staking.

I observed the same thing; my Bushys didn't have staking. They never came loose. My buddy's Bushy's castle nut did come a little loose, but didn't keep the rifle from running. I'm not sure if it was loctited or not.

No staking. You screw the buffer tube in until it hits the buffer retaining pin (holding the pin in). You install the detent and spring for the rear assembly pin. Put the A2 spacer on the end of the buffer tube. Put stock shell over buffer tube. Put some locktite on the screw. That's it.

Ok DMK, thanks. How is the A2 tube timed correctly?

 

[DMK]

How is the A2 tube timed correctly?

No timing. It doesn't matter. The tube is perfectly round. You screw it in until it stops. That's it.

I suppose you could put locktite on the buffer tube's threads, but I never have and they don't come loose on me. The screw that holds the stock on keeps it all together.

 

[ny32182]

Ah... that would make sense! Thanks again.

 

[Onmilo]

You don't screw an A2 tube in until it stops either.
If you screw it all the way in and it binds the buffer detent you will not be able to install the buffer and buffer spring into the extension tube.
You screw the buffer in hand tight, then use a wrench to tighten the extension tube just tight enough to fully retain the bufferdetent without binding.

Staking is a Mil-Specification requirement on all carbine collapsable stock retainer nuts.
If your retainer nut is not staked, it isn't Mil-Spec.