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

[Jimbo45]

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

Armalite

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.