Any chance they'll add an 11.5" to the line-up?

I ask here because I've seen them reply to other barrel topics.

That would be really nice, but they haven't even had the 20" bbls in stock in months.  And the last two barrels I ordered from them, a 12.7" and a 16", both had triangular hand guard caps that had to be replaced with round ones.  

I haven't been able to figure out the reason behind the 12.7" barrel length.  It's more than a half inch longer than it needs to be for a perm attached moderator.  A lot of guys, me included, have to cut them down further.  

Just Sunday ramblings...  

You loose 1/2" in threads. 12.7" plus 5" moderator minus 1/2" threads.  Usually comes out 16.2 to be safe.

I've seen the 12.7" size mentioned several times for an E2 build.
However, I noticed in one thread, that the 12.7" measurement was from the muzzle to the end of the barrel extension.
Here's a picture....


That's not normally how barrel length is measured. Usually it's measured from muzzle to breach face, and in the case of an ar15, the breach face sits inside the barrel extension.  I have a feeling when Brownell's made their 12.7" "moderator ready" barrels, they used the correct way to measure barrel length.

When I built my xm177e2 I used an 11.5" barrel with an ar15sport moderator, with is 4.8" long (half inch longer than a real moderator, 4.3"). I had to shim the grenade ring a bit, which gave me an extra .20", and ended up with a final barrel length of 16.125" (measured muzzle to breach face).

With the measurements from my build, I'd estimate that you would need a barrel about 12.2" in length to use a standard 4.3" moderator.

I've gone to the expense of making mine an SBR, so...

I want a 1:12 barrel that's the correct length without spending another half a barrel in removing an inch or so.

+2 on SBRing and looking for the "real" barrel length.  I'm not so worried about the 1:12 though.  I shoot a lot of 55g or larger so I'd prefer something in the 1:7 or 1:8 twist.  I would love to see chrome lined!

I just went with a Colt SP1 carbine barrel; it'll get chopped down to 12.7" and then with the addition of the Brick Moderator, it'll be 16" OAL.

Just a heads up...if you are interested in barrels, especially SBR length barrels that are true to the XM, hit Brownells up in this thread or in this link:
http://www.ar15.com/forums/t_2_333/276882_So_now_that_you_have_the_XM_moderator_with_launcher_ring____.html