Does anyone have an upper that shoots the new 6.8 SPC?

I want to buy an upper for my Bushy XM15-E2S.

What can anyone tell me about this round or upper?

So far, the only two major manufacturers of 6.8 SPC are Barrett with their M468 (way overpriced in my opinion) and Model 1 Sales (there are a few custom shops out there doing 6.8 work, but that's another matter). Model's 1's fine except that the 6.8 really likes a mid-length gas system and they don't offer one (yet). That said, most AR manufacturers are going to start producing 6.8 uppers and rifles within the next month or two. I'd say wait until December or so for production to get into full swing, for all the bugs to get worked out, and for the prices to drop, then make yourself a nice Christmas present.

As to what is this round? If 5.56 is a 9mm and .308 is a .45, then the 6.8 would be a .40 S&W. It's an intermediate round designed primarily for close to medium ranges. It has the trajectory of a 5.56 with almost the punch of a .308. There's a bunch of stuff written about it online. Just type in "6.8 SPC" into Google and read up.

Sure, we know all about it.   You should have found this tacked thread already:
AR-15 •   AR Discussions •  6.8mm SPC FAQ & Load Data

Try to do some preliminary research before posting a question that's already been asked.

-z

I am going to order a 24 in upper w/ a predator FF rail from Bravo.

I have the scope for it and the lower already.

www.competitionshooting.com has a 6.8 made by DPMS listed on their site.  

Quoted: WE KNOW A LITTLE BIT ABOUT THE 6.8 SPC: ar15.com/forums/topic.html?b=2&f=134&t=142462 WES GRANT M.S.T.N.

Wes, you are being too modest. Wes built one hell of an accurate 6.8SPC upper for me. Mine is a 16.5" and it will shoot! Sub-MOA is an under statement by Wes. Do a search on the Twins. Here's a pic before they came home that was taken by Wes. Twin #2 is in 5.56MM. Both have are 0.5MOA easly with the right ammo.

Quoted: I am going to order a 24 in upper w/ a predator FF rail from Bravo. I have the scope for it and the lower already.

I don't think a 24" tube is going to buy you much in the way of velocity. The current 6.8SPC loadings are really for 0-400M. A 16.5-18" are the optimal barrel lengths. A 20" may buy alittle more, but 24" is a lot of barrel for very little gain.

Edited: Damn, I wish I could spell, but after all I am an Engineer. We are not known for our spelling.

18" 6.8SPC from MSTN-
[ link to larger image ]

With commercially-available powders, you'll get maybe another 50fps going from 18" to 20", and lose about that much going from 18" to 16".    Since 6.8SPC has a smaller case volume to bore ratio (ie, it's less overbore) than 5.56 and 308, it benefits less each additional inch of barrel.  

Since there are no rifle-length gas systems in 6.8SPC, that's one less reason to go 18".    

Damn Zak - your 6.8 probably has more stocks and forends than most of the prototypes!  Probably more ammo through it too!  I think I remember seeing a picture of a huge haul of 6.8 ammo that you posted - was that factory or your reloads?  Also, have you gotten a few new mags and tested them yet?

Spooky

Well, with the AWB dead, I'm running it on a new lower, hence the new color scheme.  

The huge haul of ammo was two 1000 round cases of new unfired Remington brass.   I'll be running batches of it through my Dillon 650 this fall.  My upper probably has only about 500-600 rounds through it at this point.  Up until a couple weeks ago, I was limited to the original 400 cases from March.

I've had mags for a few months, both the 10, 15, and 25 round capacities.  They work fine.

-z

Quoted: Well, with the AWB dead, I'm running it on a new lower, hence the new color scheme.   The huge haul of ammo was two 1000 round cases of new unfired Remington brass.   I'll be running batches of it through my Dillon 650 this fall.  My upper probably has only about 500-600 rounds through it at this point.  Up until a couple weeks ago, I was limited to the original 400 cases from March. I've had mags for a few months, both the 10, 15, and 25 round capacities.  They work fine. -z

I originally ran my MSTN 16.5" 6.8SPC on a Colt lower with a basic black VLTOR, I am currently running it with a LMT/Crane. I haven't tried the M93A yet. Some us are still experimenting, looking for an optimal set up (color independent). Ditto, on the ammo/brass.