Mil Spec Buffer Tubes?

[magpul_556]

I just sold my UBR and am going for the CTR, before the UBR i had a VLTOR buffer tube on my carbine. They are like $44, what is the differance between the expensive VLTOR and a $25-$30 Buffer Tube? Besides the logo what makes the price difference?

[Stickman]

There are two different sizes, and two different ways of making them. You are paying less, and getting less, including thinner threads, weaker construction, and varying dimensions.

You want a milspec receiver extension (buffer tube).

[magpul_556]

Thanks, i understood the two different sizes, but i always wondered the differences between a cheap milspec and an expensive milspec. I do agree, you get what you pay for.

[John Hwang]

I can't speak for some of the cheaper buffer tubes. But I've always like Stag buffer tube which are made at CMT who also happen to make them for Colt. I also like LMT buffer tubes.

You normally get what you pay for. I know there are exceptions to the rule but pretty rare in this business.

[Gator]

Quick question... What is it about CMT/Stag and LMT that you like? Finish? better stock fit? Id like to know as I recently got a top tier MFG milspec tube and while I am happy with fit and construction, it appears to be a bit too rough... Esp. compared to a comm. tube I have lying which is very smooth, the threads of which, to my surprise, measure exactly 1.185. They do appear cut rather than rolled on though.
Im looking into the Vltor RE but curious as to whether or not it is full milspec (forged with rolled on threads and ofcrouse, tube and thread diameter) or simply milspec in diameter?

[Specialized Armament]

A Colt receiver extension is made from a 7075 aluminum forging. Commercial receiver extensions are extruded from weaker 6061 and therefor must be made thicker to be sufficiently rigid. 7075 has twice the tensile strength and almost twice the yield strength of 6061.

The finish on the inside of the extension is of critical importance. Colt receiver extensions are as smooth as plate glass. Its extruded counterpart is often "ribbed" as a result of the manufacturing process and manufacturers find it to costly to finish the interior and maintain price point. All of those ribs are essentially speed bumps working against the action spring and slowing the bolt group.

Many extruded extensions are also not threaded properly. The threads are eccentric to the tube. In most circumstances barely noticeable but sometimes enough to bind the action to the point of short stroking when combined with the ribbing found inside the extension and/or weak ammo.

Next time you are in the market for a receiver extension and aren't buying Colt, make sure you "finger" the inside of the extension and eyeball it from the top down to see if the threads appear to be concentric to the extension.

[rob_s]

To add to the above, every company I've contacted re: their "milspec" extensions is making them out of extrusions. If you are shopping and want the cheaper option, I'd at least verify that it's a 7075 extrusion and not just a 6061 extrusion made to the milspec OD. IMHO a 6061 extruded extension with the milspec OD would actually be WORSE than a commercial extension.

[Specialized Armament]

Can 7075 even be extruded (hollow extrusion)?

[rob_s]

Can 7075 even be extruded (hollow extrusion)?

Great question, and I don't know. To date all of the manufacturers I've contacted re: their "milspec" tubes extrude them and acted like I was nuts for asking if it was forged. I don't recall asking, or getting answers to, the material used. Will check on that.

[rob_s]

Here's one that claims to be milspec OD but is extruded 6061

Armalite (http://www.armalite.com/ItemForm.aspx?item=15207020&Category=93c41860-4ca2-43ee-8ca9-dc09b1a5bf2c)

[Jimbo45]

Here's one that claims to be milspec OD but is extruded 6061

Armalite (http://www.armalite.com/ItemForm.aspx?item=15207020&Category=93c41860-4ca2-43ee-8ca9-dc09b1a5bf2c)

What other brands of "milspec" tubes are of extruded 6061, are you aware of? This is interesting.

[Gator]

I dont want to ask and cause a frenzy as to which Milspec tube MFGs extrude theirs so can anyone point out those who actually forge theirs instead? Lets throw in those who roll their threads on as well.

[ggt1_02]

Can 7075 even be extruded (hollow extrusion)?

Yup, sure can.

[rob_s]

What other brands of "milspec" tubes are of extruded 6061, are you aware of? This is interesting.

Working on finding out. Armalite was the only one that had it on their website. I believe that DSA also uses 6061 but am not certain.

[markm]

I've been beaten down by goofballs on other forums for advising against the use of commercial REs... even after pointing out many of the non debateable points above.

[rob_s]

Stage (CMT) has replied that their extensions are extruded 7075.

This might turn out to be something else added to the Chart.... could even be two rows, one for forged/extruded and one for 7075/6061. I would rank them in order as
1: forged 7075
2: extruded 7075
3: anything 6061 (although I don't imagine anyone is going to bother forging 6061)

[Jimbo45]

Yes, this sounds like a good addition to the chart. Good to hear that Stag has given information on this, and I am curious to hear other manufacturer's claims. It is a little bitter sweet, because the guns that I have built, use CMT extensions. I guess it could be worse.

Next question: has anyone ever seen a failure, or a breakage of a receiver extension, regardless of method of construction?

[markm]

Next question: has anyone ever seen a failure, or a breakage of a receiver extension, regardless of method of construction?

These are usually the result of an extraordinary impact of some kind. I've seen one pic on another forum where some nut was testing some gadget for impact and he chucked the rifle up and broke the MIAD and the commercial RE.

Another SME on one site noted the 3 that he had seen break.

Usually the RE rips out of the lower due to the threads on the tube being out of spec. (correct pitch, but too short)

[Gator]

Any info on Vltor RE's? BCM?

[223nbecker45]

How about Larue?
I'm going to get Vltor or Larue.

[pezboy]

Does anyone know of any mil spec 4 position REs? CMT? Some websites don't state how many positions they have.
Dustin

[markm]

Does anyone know of any mil spec 4 position REs? CMT? Some websites don't state how many positions they have.
Dustin

I just ended up with CMT 5 pos REs on some of my guns. The old Colt 4 Pos RE's were commanding too much money IF you could even find them.

I run the older "N 1" Colt stocks on them and there's no issue. I just have an extra position.

[pezboy]

I just ended up with CMT 5 pos REs on some of my guns. The old Colt 4 Pos RE's were commanding too much money IF you could even find them.

I run the older "N 1" Colt stocks on them and there's no issue. I just have an extra position.

5 will be fine. I recently got one that I thought would be 4 or 5 position and it has 6. There are way too many adjustments and they are in different places than my other rifles.
Dustin

[Jimbo45]

I just ended up with CMT 5 pos REs on some of my guns. The old Colt 4 Pos RE's were commanding too much money IF you could even find them.

I run the older "N 1" Colt stocks on them and there's no issue. I just have an extra position.

Hmmm. All 5 of the CMT tubes I have, are 6 position. Are they making them 5 now?

[Stickman]

How about Larue?
I'm going to get Vltor or Larue.



Vltor machines their own, no idea who makes the other.

[ColdDeadHands]

Does anybody have experience with the D.S. Arms Mil-Spec tube? GTG?

[DMGunn]

Does anybody have experience with the D.S. Arms Mil-Spec tube? GTG?
I am curious about this also, as I have several. I know one thing - they are ever-so-slightly tighter on my E-mod than the VLTOR tube, but that isn't a problem since I don't generally adjust the length anyway, and I love the absence of rattles.

[ColdDeadHands]

I went with the BCM Kit

[NavyDavy]

Working on finding out. Armalite was the only one that had it on their website. I believe that DSA also uses 6061 but am not certain.

Can anyone verify the DS Arms mil-spec extension tube is made from 6061? I just put one on my carbine, and now I'm concerned.

[ripper]

I have a newer DPMS carbine and it came with a commercial extension. I am not all that mechanical - can I replace the existing extension with a milspec variety?

[Venom]

yes, no problem; just get yourself the right tool for the extension and its normally a thing of 5 mins to swap them.

[ripper]

Thanks for the information . . . in process.

[Shrockp]

Just remember that when you change them out you will need to change stocks as well

[Exporter]

Here's some info from Paul @ Bravocompany:

"Milspec receiver extentions are machined from 7075T6 Impact extrusions, they are not forged.
No such thing as a milspec forged receiver extension.

An impact extrusion is NOT the same as an extrusion. "

Original Post: http://www.ar15.com/forums/topic.html?b=2&f=138&t=187490

[Specialized Armament]

Here's some info from Paul @ Bravocompany:

"Milspec receiver extentions are machined from 7075T6 Impact extrusions, they are not forged.
No such thing as a milspec forged receiver extension.

An impact extrusion is NOT the same as an extrusion. "

Original Post: http://www.ar15.com/forums/topic.html?b=2&f=138&t=187490

What is the point of your post? If you came in here to draw fire, mission accomplished...

[Exporter]

Sorry, I thought everyone was discussing RE's and I was trying to share info.
You asked the question "Can 7075 even be extruded (hollow extrusion)?" and I thought the info. would help.

[Specialized Armament]

Sorry, I thought everyone was discussing RE's and I was trying to share info.
You asked the question "Can 7075 even be extruded (hollow extrusion)?" and I thought the info. would help.

While I can appreciate your addition to the thread, there are way to many engineering terms being used and I doubt any two people are applying the same definition. Paul's contribution to the manufacturing process of a receiver extension is correct but overly simple. I may be willing to argue that impact and forged are equally descriptive of the process but neither entirely correct. The point of the thread I believe was a 7075 v. 6061 question moreover than the exact process by which the two are manufactured.

[Quentin]

I ordered the BCM receiver extension kit with H-buffer and Gen 2 stock and hope to get it in a couple days. Time to replace a Del-Ton commercial tube and figured BCM would be as good as any out there.

[Jimbo45]

While I can appreciate your addition to the thread, there are way to many engineering terms being used and I doubt any two people are applying the same definition. Paul's contribution to the manufacturing process of a receiver extension is correct but overly simple. I may be willing to argue that impact and forged are equally descriptive of the process but neither entirely correct. The point of the thread I believe was a 7075 v. 6061 question moreover than the exact process by which the two are manufactured.

I don't understand your hostility, here!? He was simply contributing info, that came from Paul!? I understood the post just fine, but not sure what you are getting at. The OP never even mentioned 7075 vs. 6061, but was asking the DIFFERENCE in milspec and commercial tubes....I think process of manufacture would fall within this discussion, no?

[Skintop911]

I don't understand your hostility, here!? He was simply contributing info, that came from Paul!? I understood the post just fine, but not sure what you are getting at. The OP never even mentioned 7075 vs. 6061, but was asking the DIFFERENCE in milspec and commercial tubes....I think process of manufacture would fall within this discussion, no?

<obs>
Jimbo, take it easy. That was not even remotely hostile. When you see hostile from SA, it will be unmistakable.
</obs>

[Jimbo45]

<obs>
Jimbo, take it easy. That was not even remotely hostile. When you see hostile from SA, it will be unmistakable.
</obs>

Ok, I agree, hostile maybe was a strong word. How about "standoff-ish"? Just wondered where it came from....seemed relavent to me.?

[5pins]

I agree with Jimbo. I found Exporter’s post to be relevant and interesting, and SA’s response unnecessary.

[Dos Cylindros]

I agree with Jimbo. I found Exporter’s post to be relevant and interesting, and SA’s response unnecessary.


So did I. I will say, SA is without debate one of the foremost experts on the ar platform and his advice and knowledge should be strongly considered when debating anything related to the AR platform and it's reliability/durability/performance. That being said, I also know there is a very strong Colt bias (or perhaps preference is the better term), and often an unwillingness to consider anything that is not Colt to be an inferior product. Colt is deffinately the top of the heap for AR manufacture, but there are a few other companies that make very high quality ar platform weapns, BCM and LMT come to mind.

[Specialized Armament]

Apologies to those whose skin is a bit on the thin side. The WEVO staff is welcome to remove all of our posts from the thread.

[Stickman]

The internet is a funny thing, comments that are meant one way can be taken many different ways. I don't think anyone is being insulting, we are all on the same side here. This is a nonevent as far as I'm concerned.


If it makes anyone feel any better, I'm convinced that after the day I had, you guys should all buy me a beer. :P