I've acquired a few ARs over the years, and one thing I've noticed is that the interior finish of the buffer tube really has a significant impact on at least the perceived smoothness of the gun's operation.

My first AR was all PSA parts from about 10 years ago. It's well put together and has a smooth finish on the inside of the tube, and the outside is the correct diameter for a slop-free fit to an MOE stock. It's a good running gun, with very little twang or spring noise.

The lower that I put in my recent 9mm build is similar. I don't remember where I got that tube from, but it's smooth and quiet.

My 20" rifle build tube is horrible. It's actually ribbed inside...and not for anybody's pleasure. It creates all kinds of spring noise and it feels like a bolt on a cheese grater when you pull back the charging handle. No amount of grease , flat-wire springs, or even those "silent-captured" recoil assemblies are going to fix it.

I'd like to replace that one, and a couple of others that I have, but I don't remember what brand they are in order to avoid them, and most online reviews don't speak to the interior finish of the tubes, so it's hard to know what you're getting. Does anybody have any recommendations for a quality buffer tube that's smooth inside and not outrageously expensive?

been a few years since I have bought any Receiver Extensions, but RRA was good to go then,

excellent quality,

I have 2 favorites.

Carbine Length Receiver Extension --> LMT AR-15 Carbine Buffer Tube - They aren't often in stock but hands down they are my favorite. I just ordered one to replace an OEM Colt RE and then I'll be all LMT for Carbine REs.

VLTOR A5 Receiver Extension --> BCM® Intermediate Receiver Extension (A5 Buffer Tube)

I'm not sure what qualifies as 'outrageously expensive', but considering the RE is an integral functioning part of the rifle, $40-ish bucks, plus or minus, isn't 'a lot' IMO.

I have had a couple of PSA tubes that were ok, some where threaded too long to the point you couldn't full collapse the stock, among other 'dislikes'. Sure, they functioned fine but I'll pay the extra $20 to get a 'good one'. Over time I have sold them off and replaced with LMT REs as I have found them.

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VLTOR A5 Receiver Extension --> BCM® Intermediate Receiver Extension (A5 Buffer Tube)

I've looked at this one...anything special you have to do with springs and buffers since it's "intermediate"?

This conversation makes me an odd duck. I have never bought from people who are known to be extremely cheap and low quality like PSA, I avoid them. But I have at least 100+ buffer tubes that I have purchased from a long list of vendors over time and none of them have any issues. I think if you avoid the dregs you will have very good luck. The latest ones I have came from Geissle only because I can remember short term and they were mint.

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Originally posted by 92fstech:

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VLTOR A5 Receiver Extension --> BCM® Intermediate Receiver Extension (A5 Buffer Tube)

I've looked at this one...anything special you have to do with springs and buffers since it's "intermediate"?

Yes, you need to use "A5" Buffers (longer) and a rifle buffer spring. Basically it gives you more weight options (A5H0 through A5H0, ranging from 3.8 to 6.8 oz) and combined with the longer spring, is supposed to lower bolt velocity and felt recoil. You CANNOT mix A5 and Carbine components or bad things will happen.

I first used it on my 11.5 SBR (BCM Upper) - with a suppressor, it is a bit overgassed and I found that the A5 system with an A5H2 and Green rifle spring worked a lot better than the H2 & H3 and a Blue Carbine spring.

I also put it on a 16" BCM AR15 and like it a good bit, but if you have a well running carbine RE working I don't see it as a 'must have' unless you think you need it. So I have kept my others Carbine REs with H2 / Blue SpringCo.

Just make sure you get mil-spec tubes made from 7075 aluminum alloy. ALG, Geissele, Magpul (with 7-pos instead of 6), and Aero are all fine.

Lately I've used the Aero enhanced ones with the lower tang that curves forward and surrounds the detent. Supposed to avoid carrier tilt and can't unscrew even if the castle nut comes loose. The machining quality and finish are outstanding.

Never considered this.
Mine is a PSA parts build for the most part & it's a smooth/quiet operating rifle, on a commercial-spec tube.
The other 2 I have any time behind were both DPMS factory builds & I remember them being a bit more 'twang'-y.

The PWS Enhanced Buffer Tube is a favorite of mine.
Pricey but amazingly built.

CMC makes a good kit. 7075, QD plate, and made in the USA for a very competitive price.
It's my go to, now.

Bruce

I have Geissele and LMT and both are excellent. The LMT in particular for it's exterior finish.

I have 4 AR's at present. One I build from parts, the other three (at least the lowers) were factory assembled and I have no idea whose buffer tubes are in any of them. The one I built was on a RR receiver and parts kit, but I'm not sure whether the tube was RR or not. The only one that has an annoying twang is my Colt A2 HBAR that I bought in the mid-80's.

Colt and Knight’s do not have civilian assembly lines for their 556 products so whatever you buy from them is something that is battle tested and has endured decades of government inspection and competitors scrutiny.
so there’s that

I have no issues with Colts REs except they only have 4 adjustment positions. I replaced both Colt REs with LMTs just because of that.

BCM is another great manufacturer / provide of quality REs. I only have their A5 tubes, but I'm sure their Carbine REs are just as good.

Whatever you decide on, take a rag, spray an area big on it with your favorite oil. Then rap the oiled rag around the spring and screw the spring through the oiled section. It will leave the thinnest coat of oil on the spring. It does help with smoothness and quiets it down a bit. I’ve been doing this for years. No issues to date.

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Originally posted by 92fstech:
...It's actually ribbed inside...and not for anybody's pleasure...

Excellent, sir, excellent Made me laugh, made my wife upset at my laugh, excellent.

In the carbine receiver extension category, LMT is hands down the best. The BCM A5 receiver extensions are great too, but they force you to use an A5 buffer. I still use carbine REs. Just personal preference.