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7/30/2026 7:07:14 AM EDT
I have one lower left to build.

I am considering a 6.8 SPC build.

Based on my research, I am thinking a 12.5 inch barrel.

Question is: do I want a midlength or carbine gas system?

I will likely use a free float handguard.

Thoughts and/or suggestions?
7/30/2026 7:21:43 AM EDT
[#1]
Mid length gas on a 12.5    Have you looked at the Blackstone Arms Barrels?
7/30/2026 7:38:12 AM EDT
[#2]
Quote History
Originally Posted By LoudLyle:
Mid length gas on a 12.5    Have you looked at the Blackstone Arms Barrels?
View Quote


This, exactly what I run, except mine says AR Performance on it
7/30/2026 7:59:51 AM EDT
[#3]
I have one of each length,the mid length is less "harsh" than the carbine length.Both have caused White tail to be converted to food @ ranges up to 250yrd.
7/30/2026 9:04:40 AM EDT
[#4]
12.5" middy is exactly what I'm going with.
7/30/2026 10:29:04 AM EDT
[#5]
12.5" mid length
An armed society is a polite society.
7/30/2026 10:36:57 AM EDT
[#6]
I have a 12.5" midlength SBR.  It started as an ARP (now Blackstone)  14.7" mid that I had cut down.  I shoot it suppressed all the time, but I think it would run fine unsuppressed if I went with a lighter buffer.
7/30/2026 2:55:37 PM EDT
[#7]
I was considering a RRA upper then having it cut down.  

I like the fact I could order it with a pinned low profile gas block.

Im thinking this is the cheaper route, as it includes BGC also.
7/30/2026 5:08:09 PM EDT
[#8]
What are you going to do for ammo?

Ive been wanting to build one for a while as well. I don't need a ton of ammo for hunting
Do Good
Be Dangerous
Live Free
7/30/2026 5:27:20 PM EDT
[#9]
Quote History
Originally Posted By 03RN:
What are you going to do for ammo?

Ive been wanting to build one for a while as well. I don't need a ton of ammo for hunting
View Quote



There's ammo available.

OP, Blackstone Arms is the answer to 6.8 Spec II. The best barrels ever made for that caliber are the ARP barrels. I've run them since 2008, and was part of testing for several ammo companies developing spec II ammo. Spec II today is pretty much handloaders. We get about 150-200fps more than the commercial ammo, and it's at the 55,000-58,000psi area exactly what the standard ammo is in the original chamber.

With Blackstone, you get a barrel and extension. Go ahead an buy his bolt. It's a good one. Any carrier will work.

He does everything on the barrels exactly like Harrison did at ARP, that was the stipulation to buying the barrel company. Everything had to be exactly as Harrison had it, or he wouldn't be able to use the name. I've got two of the barrels from Blackstone, and they're identical.

If you have any questions, call him at Blackstone, ask one of the 6.8 shooters here or go to 68forums and join up. You should do that anyway, and he's on that site all the time.

Good luck, and welcome aboard.
7/31/2026 11:19:50 PM EDT
[#10]
Quote History
Originally Posted By 03RN:
What are you going to do for ammo?

Ive been wanting to build one for a while as well. I don't need a ton of ammo for hunting
View Quote

Druid Hills Armory has an assortment of loads .

Im now following this thread haha .


8/1/2026 5:38:19 AM EDT
[#11]
Originally Posted By 03RN:
What are you going to do for ammo?

Ive been wanting to build one for a while as well. I don't need a ton of ammo for hunting
View Quote
Whatever you do, OP, start buying ammo and brass (if you reload) now.
Stuff I learned from A-Team: 1)Always pity da fool 2)Carry wire cutters (you may need to defuse a bomb or start a car) 3)Never trust a crazy fool 4)Carry grenade launcher/machine guns in the van 5)Know how to weld 6)Love It When A Plan Comes Together
8/1/2026 9:03:55 AM EDT
[#12]
I'm running mid on my 2 builds.  I went with Bison and very happy.  I've been in on 6.8SPCII far enough back I still have a Kotonics barrel in use.  Glad to see you going 6.8!
8/1/2026 9:36:31 AM EDT
[#13]
I have 3 6.8's now. A 16" with midlength gas. A 16" Adam's Arms piston with midlength gas, and an 8" with pistol gas. Love all 3.

Check the EE often, as there are some pretty good deals on barrel/bolt combos. That's how I got the 8" one.
I hated going to weddings. All the grandmas would poke me and say "You're next". They stopped that when I started doing it to them at funerals.

Sic semper evello mortem tyrannis
8/1/2026 11:43:49 AM EDT
[#14]
Quote History
Originally Posted By 50cal:
I have 3 6.8's now. A 16" with midlength gas. A 16" Adam's Arms piston with midlength gas, and an 8" with pistol gas. Love all 3.

Check the EE often, as there are some pretty good deals on barrel/bolt combos. That's how I got the 8" one.
View Quote

Do you prefer the DI or piston one better?
Do Good
Be Dangerous
Live Free
8/1/2026 7:26:03 PM EDT
[#15]
Quote History
Originally Posted By 03RN:

Do you prefer the DI or piston one better?
View Quote
I like the piston one a bit better. I stick the Rex MG7 30cal can on it periodically during deer season and it works great.

I came into the AA piston kit really cheap at a yard sale. I think i gave $20 for it. The complete set up was there.
I hated going to weddings. All the grandmas would poke me and say "You're next". They stopped that when I started doing it to them at funerals.

Sic semper evello mortem tyrannis
8/1/2026 10:51:46 PM EDT
[#16]
Quote History
Originally Posted By raverill:


This, exactly what I run, except mine says AR Performance on it
View Quote

Same.

I don’t so it it much. But hot damn. I love that SBR.
Esstac’s Retarded Social Media Influencer
8/2/2026 7:46:09 AM EDT
[#17]
Quote History
Originally Posted By 9D1Alpha:

Druid Hills Armory has an assortment of loads .

Im now following this thread haha .


View Quote View All Quotes
View All Quotes
Quote History
Originally Posted By 9D1Alpha:
Originally Posted By 03RN:
What are you going to do for ammo?

Ive been wanting to build one for a while as well. I don't need a ton of ammo for hunting

Druid Hills Armory has an assortment of loads .

Im now following this thread haha .




Druid hill also makes spcii spec ammo for cavity back bullets.  I have had great results hunting with standard pressure 110 grain s&b pts ammo.  I will be trying some Druid hill in the near future, most of their offerings are cheaper per round than buying hornady ammo and they are 50 round boxes.
8/2/2026 7:56:13 AM EDT
[#18]
Quote History
Originally Posted By REAPER2502:
I was considering a RRA upper then having it cut down.  

I like the fact I could order it with a pinned low profile gas block.

Im thinking this is the cheaper route, as it includes BGC also.
View Quote


RRA will make a 14.5” 6.8 spcii upper and size the gas port for unsuppressed or suppressed shooting.  It’s not listed on the website, you would have to call and order.  I am considering building an a2 upper with fsb 6.8 rifle and RRA was very quick in responding to questions about a year ago regarding 6.8 options.  

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