PDA

View Full Version : 6.8 SPC build


DWill
03-10-2007, 7:55 PM
I am about to start my first build and appreciate the knowledge that is shared in this forum. Will a 5.56 lower work with a 6.8 SPC upper?

gn3hz3ku1*
03-10-2007, 8:00 PM
i dont think so

Prc329
03-10-2007, 8:08 PM
A lower is a lower. You can use any 5.56 lower with any ammo that will feed from a standard type mag. 6.8 mags are basically modified 5.56 mags with changed feed lips and follower.

The 6.8 upper is the same except the bolt and barrel.

C.G.
03-10-2007, 8:10 PM
I am about to start my first build and appreciate the knowledge that is shared in this forum. Will a 5.56 lower work with a 6.8 SPC upper?

No problem. Aside from the 6.8 SPC a 5.56 lower will also work with 6.5 Grendel, .50 Beowulf, 9mm, 7.62 x 39, .458 Socom and bunch of others.

tenpercentfirearms
03-10-2007, 8:11 PM
Any standard AR15 lower will accept 6.8mm magazines. The magazine is the only part of the lower receiver that is not the exact same in a 6.8 SPC build. For example. My LMT Defender 2000 with bullet button only needs to have the 10 round magazine changed and then I can swap my barrels on my LMT MRP CQB and the bolt carrier group and away I go.

gnehzekul is incorrect.

Prc329
03-10-2007, 8:12 PM
As Cg said there are many rounds that will work. As long as the mag is not bigger then the magwell it will work with the lower.

gn3hz3ku1*
03-10-2007, 8:15 PM
ops i guess i was wrong .. thanks for the info guys

thmpr
03-10-2007, 9:22 PM
Just remember that any 5.56 lower will work with calibers with OAL of 2.260" Thats the best way to remember...:D

DWill
03-11-2007, 1:13 PM
Now, what 6.8 upper would you recommend? I'm not looking to pay a premium price.

Technical Ted
03-11-2007, 1:31 PM
Now, what 6.8 upper would you recommend? I'm not looking to pay a premium price.
Definitely save your money for ammo. At MINIMUM you're going to be paying $14 per 20 rd box and that's if you buy in 200 rd case lots.

Unless you reload in which case it can go down to around $0.60 per round.

There will be no military surplus 6.8 SPC anytime in the foreseeable future.

If you're looking for a plinking gun, stick to .223 Remington/5.56 NATO.

Buying a low end upper to shoot expensive ammo is inefficient.

Stag Arms uses a non-standard muzzle thread (1/2-36) instead of what has become an industry standard (5/8-24)

Look into CMMG 6.8 uppers:
http://cmmginc.secure-mall.com/shop/?shop=1&cart=617807&cat=44&

Bushmaster just released their 6.8 uppers recently:
http://www.bushmaster.com/shopping/uppers/pre-ban/bura3b16m468.asp

JPN6336
03-11-2007, 3:06 PM
RRA is also planning on releasing 6.8 SPC Uppers sometime in the near future.

bwiese
03-11-2007, 3:09 PM
RRA is also planning on releasing 6.8 SPC Uppers sometime in the near future.

I hope they know how to read the (defective) SAAMI specs - perhaps they'll somewhat duplicate the Barrett or Noveske chambers.

gn3hz3ku1*
03-13-2007, 9:04 AM
why does stag sell a 6.8 lower then?
http://ddsranch.com/store/product_info.php?products_id=582&osCsid=b5d7083663c80465b89667d26ef03cae

Prc329
03-13-2007, 9:09 AM
Because they sell a 6.8 rifle. They just added the roll mark for there complete 6.8 rifle.

Trust me cause I built a 6.8 spc. You can use any lower you want, just need a 6.8 mag/barrel/bolt.

Japedo
03-13-2007, 9:11 AM
That one looks familiar. I have 2, the only difference is the 6.8 vs the 5.56 stamp as they sell the rifle complete.


why does stag sell a 6.8 lower then?
http://ddsranch.com/store/product_info.php?products_id=582&osCsid=b5d7083663c80465b89667d26ef03cae

Paratus et Vigilans
03-13-2007, 9:17 AM
why does stag sell a 6.8 lower then?
http://ddsranch.com/store/product_info.php?products_id=582&osCsid=b5d7083663c80465b89667d26ef03cae

It also suits us anal retentive folks, who like it to be stamped 6.8 on the outside if that's what's on the inside.

I built twin Stag M4geries, one in 5.56 and the other in 6.8, and the only way I can tell them apart at a glance is from what's pinned in the magwell (PRI in the 6.8 and Bushmaster in the 5.56).

I just like having the 6.8 roll stamp on my 6.8 lower. Call me crazy. Call me anal. Oh, and please straighten up that crooked picture on your wall, too! :D

Technical Ted
03-13-2007, 9:36 AM
I put together my 6.8 SPC upper in mid-2005, months before OLL mania hit California. Originally I had it installed on my reg'd Bushmaster .223-5.56mm marked lower.
http://www.hunt101.com/img/322131.jpg

Also tried it on my Colt lower, but the whole large hammer and trigger pin thing made installing a reasonably priced 2-stage trigger more expensive.

When Wes (Tenpercentfirearms) became the first FFL to offer stripped lowers to the California public, I specifically asked him to order one of the Stag 6.8 lowers.

The only differences are that the 6.8 has a dedicated, 6.8 marked, lower and a fixed 6.8 SPC magazine.

mltrading
03-13-2007, 10:57 AM
Get a PRI upper! PRI makes excellent 6.8 upper halves and 6.8 magazines. IIRC, PRI also sells 6.8 ammo. If you need special order, let me know.:)

Prc329
03-13-2007, 11:24 AM
http://www.ko-tonics.com/KT68.html

They are supposed to build some really slick ones as well.

JPN6336
03-13-2007, 12:20 PM
http://www.ko-tonics.com/KT68.html

They are supposed to build some really slick ones as well.

From reading the threads on Barfcom their original barrels didn't meet their standards so they're working on new ones that are supposed to be ready around April 9.