Question on Buffer Tube Inner Depth

[REARSPROCKET]

Hello everyone 😁 new here and have a question that I haven't seen covered before on AR10/LR308 specific buffer tubes. I know that Armalite, KAC, Noveske, and LMT 308 tubes have a inner depth of 7+5/8" which is the original Armalite spec, but there are a LOT of other upper and mid tier companys making tubes with a 7+11/16" or more inner depth.  What is the big difference between 7+5/8" and all the other deeper length tubes if the BCG doesn't come in contact with the lower @ 7+11/16 or more depth ?

[REARSPROCKET]

and the bolt face is still in good relationship area with the ejection port opening at full rearward travel ?

[Matt.Cross]

11 minutes ago, REARSPROCKET said:

and the bolt face is still in good relationship area with the ejection port opening at full rearward travel ?

Wouldn't be easier to just ask in circumstances where the longer buffer tube actually works out, what's the difference?

The difference is that one is a great design with a great track record, and the other is just the other.

[98Z5V]

7 hours ago, REARSPROCKET said:

 but there are a LOT of other upper and mid tier companys making tubes with a 7+11/16" or more inner depth.

Do you have a list of these companies that are doing this?  And the internal depth measurements from them?

PSA had a run where they were making the .308AR Carbine extensions 8.000" internal depth, and those were garbage.  Massive lower receiver damage, from BCG impact.

[REARSPROCKET]

On 5/14/2020 at 10:54 PM, 98Z5V said:

Do you have a list of these companies that are doing this?  And the internal depth measurements from them?

PSA had a run where they were making the .308AR Carbine extensions 8.000" internal depth, and those were garbage.  Massive lower receiver damage, from BCG impact.

Off the top of my head Larue, POF, Zev, and Vltor, most are 7+11/16" which is only a 1/16" over 5/8" but some (I don't remember which) are closer to 7+3/4 or more. I measured a few on my last build and from what I remember Larue, POF, and Vltor were 7+11/16"

Edited May 16, 2020 by REARSPROCKET

[98Z5V]

12 hours ago, REARSPROCKET said:

Off the top of my head Larue, POF, Zev, and Vltor, most are 7+11/16" which is only a 1/16" over 5/8" but some (I don't remember which) are closer to 7+3/4 or more. I measured a few on my last build and from what I remember Larue, POF, and Vltor were 7+11/16"

7 3/4" that you're claiming is 7 12/16"... Or more, as you state... 

You have those, that you've stated, and you measured them. Is that what you're stating here?...

I can pile up 5 or 6 VLTORs, and give you different numbers. For a fact. All my VLTORS are dead-nuts right at 7 5/8" internal depth, too. Every one. LaRue isn't gonna fuk up an internal dimension, but I'll order one just to confirm. POF is proprietary, completely, so what they do doesn't pertain to any AR-10 spec that's out there, nor could it be accountable to one.

I think you need to get your REAL measuring glasses on, for those, or re-think what you're using to measure.  I can definitely tell you that your VLTOR numbers that you've measured, are a problem with what you're using to measure.  That is NOT accurate for a VLTOR extension. You boned something up when you checked those.

Fact.

VLTOR would LOVE to hear about this, and your long internal-depth measurements.  They would send you replacement parts RIGHT AWAY, and they'd find out what happened, on your "long" extensions.

VLTOR pioneered this, for the US Marine Corps.  They did it, to make a reliable "collapsible stock system" so US Marines could run a collapsible stock on the M16A4, using the original AR-10 Carbine receiver extension, and a special-length buffer, built by them - to make M16A4s work, with a collapsible stock.  VLTOR doesn't fuk this up.  They were the pioneers in this. They have a very solid government contract for those parts, and those exact dimensions.

BY following the original Armalite AR-10 platform, AR-10 Carbine Receiver Extension specs (7 5/8" internal depth), VLTOR made a special buffer-length to allow that AR-10 extension to work with the AR15 - most specifically, the USMC M16A4 rifles. 

You need to check what you're measuring with...

Edited May 17, 2020 by 98Z5V

[REARSPROCKET]

Relax about the Vltor, I told you from memory so I guess I was wrong about the Vltor depth, I remember selling it cause I didn't like the slightly loose thread fit in the lower. I do have a Larue still that I just remeasured again at exact 7+11/16. The POF was just a 1/32" over 5/8" not enough to matter. But there are a few 308 tubes well over 7+5/8". I like Vltor products and have a few of their other products. I've heard the Marine history of the A5 system before many times. Anyway this is off my OP question, how does extra depth length affect operation if there is no BCG contact with lower and bolt face is in good relation to ejection port window ? 

[jtallen83]

28 minutes ago, REARSPROCKET said:

I do have a Larue still that I just remeasured again at exact 7+11/16.

How about a picture of that measurement? No offense but it's one of those see it to believe things.

[98Z5V]

5 hours ago, REARSPROCKET said:

 But there are a few 308 tubes well over 7+5/8". 

 

how does extra depth length affect operation if there is no BCG contact with lower and bolt face is in good relation to ejection port window ? 

Over 7 5/8" = out of spec.  That's why I asked you about the numbers you were getting. 

Extra depth?  Timing, timing, timing...