Would an 11.5" barrel and a KAK buffer tube make for an OAL over 26"?

If you mean either of the KAK "super" tubes, absolutely, even a 10.3" barrel makes it. If you mean "normal" length tube, including the KAK Shockwave tube, far as I know you're still gonna be a tad short.

- OS

as OhShoot commented.. my 10.5 with a KAK SB15 tube (no castle nut) is 26.75" without a muzzle device

I never took flash hider off to measure it uber exactly, but seems my 10.5" incher with super tube is more like 26.55-26.60".

- OS

I have a follow on question.  I found an SB Tactical PDW Brace in stock and want to get it.  I have a 10.5" upper that I have on a pistol lower with the original Sig Brace.  With a 10.5" upper, will the addition of the SB Tactical PDW Brace push me over the 26" OAL ruling?  Thanks.

The only thing for sure that contributes to the OAL of a firearm on the ass end is a stock/grip or the farthest extent of the firearm itself. Which in the case of an AR type firearm would be the buffer tube, and a brace has never been stated as contributing.

It's gray, push come to shove,  as to whether even the buffer tube would count on a weapon that doesn't need it for operation, though it seems to have been tacitly okayed at least in the case of Black Aces shortie shotgun type config, maybe even the brace too, not sure of the exact criteria that allowed this to qualify in length as a "firearm" in the shotshell world.

- OS

I know that the length is measured from the end of the buffer tube to the tip of the barrel, not including the device.  I am asking someone who has one if they have it on a 10.5" pistol and what is the OAL.

Looking at collapsed length of whole assembly, tube seems to be about standard "pistol" length. So should be about same as you have now (unless you're using KAK "super tube" in which case it will be shorter).

Is it important that it stay over or under 26" for legal reasons in VA or something? Or you're currently 26" or more and using a VFG?

- OS

It does. I was under the impression that if it was under 26" it could be "concealed carried", i.e. I could have it loaded in my car as a truck gun. Was I misinformed?

Or misunderstanding.  Federally, there are no OAL restrictions on a handgun/pistol. 6" or 40" all the same.  If it's 26" or more and has a VFG attached, it becomes a non-NFA "firearm", and is not to be concealed on the person.

Any other limitations would have to be by state law -- for example, what firearms and how possessed in a vehicle in VA is determined by VA.

- OS

As noted in my prior post in a similar thread, the relevance of 26" or shorter being "concealable" was a federal interpretation of the NFA of 1934.  

State laws can vary on the subject.  For example, in 2012 Michigan enacted a law that limited the OAL to 26", which was a reduction from the previous 30" but it was only relevant if someone wanted to carry the firearm as a "handgun".  

VA has a "concealed handgun permit", which implies handguns rather than any type of firearm, however the actual law is a little vague on that point.  The law specifically forbids the permit from being used to conceal a weapon other than a "firearm", which strongly suggests it is not limited to just handgun.  

When I lived in VA, I was not able to find a VA legal definition of "Handgun", nor any definitive information on whether long guns could also be carried concealed.  But, I also didn't look all that hard as I wasn't carrying an AR pistol.

Absent a specific VA law that defines a handgun as less than 26", and also prohibits carrying a concealed long gun (neither of which I ever found) you are on pretty safe ground, particularly if your "firearm" is built on a receiver logged out from the FFL as a pistol, and configured as a pistol, per ATF's definition.

DakotaFAL.....thanks.  I am PCSing to LA in the near future and wanted to have my pistol AR in a go bag in case of a catastrophic event.  My set up now is at just under 26".  I figured that If I could keep it under that number, then I should not have any issue with any state that I may go to, including PA.

My 11.5" was 26.25" with a standard PSA pistol tube, the super tube is even longer.

So......measuring from the front end of the handguard to the end of the buffer tube, I am at 25.5".  I run a troy claymore muzzle device and there is still a little room before the actual barrel.  So I would say like ~25-25.25" OAL.