AR15 Buffer tube installation help!

[DennisRL]

The buffer detent on my AR15 broke loose and it bent my detent spring...I had too replace them and thought the buffer tube must not be in far enough.

It is in only enough to catch the detent pin. If I try to go one more turn its pushing on the detents point.

Is there a way to test that the detent is held in place correctly without firing?

I repeatedly charged and dry fired and recharged the rifle...I couldn't get it to pop loose.

 

[ants]

It's part of the 'fitting' of a gun together...

You file down the leading edge of the buffer tube (where it touches the skinny part of the pin) until the tube is fully seated (to torque specification) tightly into the lower receiver but still holds the detent pin down (while allowing the pin's normal movement). Don't overfile or it won't hold the detent down. Just a little at a time till it's just about perfect.

You DO want the tube to be tight.

And you DO want it to hold the pin down,
but allow it's up-n-down movement.

 

[Z-Michigan]

It is in only enough to catch the detent pin. If I try to go one more turn its pushing on the detents point.

Is there a way to test that the detent is held in place correctly without firing?

It sounds like it's in correctly. Most carbine buffer tubes will only lightly catch the buffer retainer.

As for testing, if it holds now, it should be fine. The buffer retainer is largely a convenience and ease of reassembly feature, and the rifle will work just fine without it - you just will have a small juggling act when closing the upper receiver on the lower.

 

[ants]

Hi Z-Michigan.

My response assumed a rifle buffer tube.
Those are generally torqued tightly.

Your response assumed carbine.
Those tubes have a lock nut, and can be locked down
with the tube lightly catching the buffer retainer pin as you describe.

Maybe our friend Dennis can clarify which one he has.

If he has a carbine stock, your response is most appropriate.

 

[DennisRL]

It is a collapsesable stock on a carbine.

Thanks.

 

[sansone]

on the carbines I screw-in the tubes without the detent & spring until the upper won't shut, then back-out just enough to allow the upper to shut.
Then I take notice of that depth of threads, reinstall with detent in place.
If tube notch needs slight altering I do so. More important to get as many threads engaged as possible with thin-walled aluminum