This is my first AR.  I have an RRA buffer 6-position buffer tube. I screw it on per the instructions.  As the buffer tube comes in contact with the buffer retainer it pushes it down slightly.  Is this a problem?  Do I need to file off a little bit of my buffer tube?  Thank you.

As long as the retainer still retains!

It should certainly not contact the wider part of the retainer.

As the force from the buffer is in axis with the barrel, how does it "push it down slightly"?

Well the retainer's retaining point is sloped, it's not a perfect 90 degree angle, so as the buffer is screwed on it pushes it down slightly until it's finally in contact with the post in a perpendicular fasion and won't screw in anymore.  However, this does push the retainer down in to it's hole a couple/three millimeters.

Is this a problem?

Yep, it should keep the retainer in place but not get stuck against the narrow pin of the retainer.



Since the retainer is slightly tapered at the base of the narrow part (acting as a wedge), the buffer tube will push the retainer down ever so slightly as it is screwed in.  At least this is the case on my lowers.

Edited to add: ya beat me to it, wyv3rn. [:)]

Here it is with the buffer not screwed in all the way:

[img]http://www.mti-security.com/up1.jpg[/img]

Here it is with the buffer screwed in all the way:

[img]http://www.mti-security.com/down1.jpg[/img]
[img]http://www.mti-security.com/down2.jpg[/img]

Notice the extra space as the retainer has been pushed down a bit.



What do you mean?  You mean the retainer should not get stuck against the buffer and not go down?  I don't quite understand.

Looking at the PICs it appears that you are missing the receiver end plate. That fits between the buffer tube and the lower and acts to hold in the take down retainer and spring. Some aftermarket ones are fitted with a sling slot. If this part is missing, this is what is causing your problem.

No, the plate is there.  It's the ring on the buffer tube, between the receiver and the buffer tube locking ring.



Do I have a problem?  Are you confirming that this (buffer tube against buffer retainer) is infact a problem or is this perfectly ok and normal?

Can you push the retainer in to remove the buffer without re-loosening the buffer tube?
Is is jammed tight?

If the buffer tube is bottoming on the retainer and not the backside, that is bad. In other words, if the retainer was not there, could you tighten it more?

It's pretty tight, there's a lot more resistance to it going down.



_Maybe_ 1 more turn.  I thought this was fine though?  I've seen pics of other people's AR-15's with the threads sticking out behind their locking rings.  I thought this is what the locking ring was for?

You are right, it is there, my bad. But take a look at the lower photo about 11 oclock on the buffer tube. Is that a notch for the stop to fit into? Never seen one before but if all the parts are there it might be an explanation.

Edited to correct myself. NEVER MIND Damn, I just got to start wearing my glasses when I look at things.

Check this link to make sure you got all the parts.

[url]http://www.dpmsinc.com/10Expand.asp?ProductCode=CS-M4P[/url]

There is a small raised portion on the end of the buffer tube that goes for about 1/3 of it.  This is the bottom of the buffer tube, you can see the raised part in it's entirety in picture #1 when the buffer is cocked at a 90 degree angle from the receiver.



I have exactly all those parts, thank you though.

I just tried this, it takes 2 full turns.  However, the retainer hole is completely covered up (maybe a sliver showing at most).  And the buffer is locked pretty tight into the receiver even without the locking ring.  I still don't think this is abnormal, all the buffer tubes I've seen have like 2" of threading it seems.

Thanks for the help guys.  I just solved my problem... took a dremel to the buffer tube and just shaved a little bit off the edge. [:D]

Copied this from the TM on installation of an M-4 Stock and bufer Tube.

Look on page 3-81 of TM9-1005-391-23

You can find it here  [url]http://www.ar15.com/content/books/[/url]


6A. Lubricate threads of lower receiver (5.1) and lower receiver extension (5.2) with molybdenum disulfide grease
(item 19, app D) before reassembly.
6B. Pre-position the spring (5.3) and buffer retainer (5.4) into the retaining hole of the lower receiver (5.1). Screw the
locking nut (5.5) onto the lower receiver extension (5.1) with the three notches on the locking ring (5.5) facing
forward.
6C. Align the receiver end plate (5.6) onto the lower receiver extension (5.2) with the lug of the receiver end plate
(5.6) facing forward.
6D. Pre-position the takedown pin (5.7), detent (5 8), and spring (5.9) in lower receiver assembly (5.1).
6E. Push down on the buffer retainer (5.4) and spring (5.3) and at the same time, screw the lower receiver extension
(5.2) in until it retains the buffer retainer (5 4) in position.
6F. Align the lug of the receiver end plate (5.6) into the rear of the lower receiver (5.1). Screw the locking nut (5.5)
forward until it contacts the receiver end plate (5.6).
6G. Using the special tool (Item 12, app C) tighten the locking nut (5.5) until snug.
6H. Using the special tool (item 12, app C), and torque wrench, torque locking nut (5.5) to 40 ±2 inch pounds.
6J. Stake the receiver end plate (5.6) in 2 places across from the notches in the locking nut (5.5).

I followed these instructions more or less.  I'm not about to go posting my problems on the board if I didn't atleast follow directions.  The problem really has to do with parts from different vendors just not fitting.  So some minor fitting was required.  My guess is it is the FAB-10 receiver I am forced to use has the buffer retainer hole drilled just a little further back toward the rear of the rifle than it should be.  Maybe 1mm or so.



CLP works fine.  If I need/want to use something heavier I'll use TW-25B.



Did that except I put the notches outward, I like the tiny notches outward and the wrench notches on the inside.  Less likely to snag anything on those wrench notches when they are inside.  Doesn't affect anything, I've seen many people do it.




Did all that.



Sorry, don't have a torque wrench I can use with my buttstock tool.  It's plenty tight but not too tight.  And I'm certainly not going to stake it into place.  It's not going anywhere, trust me.

"Sorry, don't have a torque wrench I can use with my buttstock tool. It's plenty tight but not too tight. And I'm certainly not going to stake it into place. It's not going anywhere, trust me."

Dont sweat it. 40 inch pounds is 3 1/4 foot pounds. That is hand tight and just a bit depending on the size of the fastener.