The Down Range Forum

Member Section => Tactical Rifle & Carbine => Topic started by: tfr270 on May 20, 2010, 06:43:35 PM

Title: 6.8 SPC questions
Post by: tfr270 on May 20, 2010, 06:43:35 PM
I'm bored. I'm injured and sitting at home since I can't go to work. So, what do I do? I start thinking about an AR. I'm on the internet surfing around and checking stuff out. All kinds of questions...anyone else here think AR-15.com is laid out weird?

Anyway, I see that new caliber, 6.8 SPC, being offerred in various AR's. I do a little digging and find out it's close to a .270, one of my favorite calibers. So, what is the deal? Do any of you have any first hand knowledge/experience with this caliber? Is it going to be the new thing for the military? Price and availibility ok? Sounds good to me...I can put this rifle in a scabbard in the jeep and deer hunt, shoot pigs and coyotes, have enough firepower just in case I run into growers and need to put out rounds while high tailing out of there. Seems like a nice all around caliber to have in an AR platform. I'm looking at a Stag Model 5 which seems like a nice EBR that I'd enjoy shooting.
Title: Re: 6.8 SPC questions
Post by: kilopaparomeo on May 20, 2010, 06:55:18 PM
It's not really a new caliber as it has been out since at least 2003 or 2004.

The bullet is a .270 caliber and most loadings are 90-115 gr that will do 3000-2650 fps in those weights.  You occasionally see heavy bullet loads at 130 gr but I don't think that is the sweet spot for the caliber.  The case is based off the old .30 Remington.  While some people try to make it into a .270 Winchester "lite"....it really isn't.  It is a good solid intermediate round that has better terminal ballistics capability than the 5.56.  It's closest competitor is the 6.5 Grendel...the Grendel is a better round beyond 300 yards and many would say that the Grendel is the same as the SPC inside 300 yards.

No it is very unlikely that the caliber will be the new military round.  In fact, I'd say there it is extremely unlikely that the military will select a new round anytime soon...more likely to keep incrementally improving the 5.56x45mm.

As you've probably read, it was developed with the help of some SOCOM guys and Remington had the first chamberings.  The round has gone through some growing pain but it seems to have worked out now.  The original SAAMI chamber specs were too tight and the old 1:9 and 1:10 twists were too fast.  Gave too high pressures.  The new SpecII chambering is better with the longer leade and 4 groove 1:11 twist barrels allow hotter  loads (like the SSA Combat Loads).  Remington still puts a large rifle primer in the round but everyone else is putting small primers.  I use Starline brass myself.

I load my own 6.8 with Sierra, Hornady and Barnes bullets in the 90-110 gr range.  H322 and Varget give the best results for me.

I think the 6.8 SPC will survive...it is being well supported by gun and ammo manufacturers.  It is a decent round.  It won't have the proplarity of a .30-06 or 5.56, but it will likely have a small but dedicated following for some time.

Here's my 6.8 SPC that I built about 3 years ago.  I've been very happy with it and would not feel undergunned against any 2 legged predator and would confidently take any game that I would otherwise use a .30-30.

(http://i37.tinypic.com/2w6ap8w.jpg)

6.8 SPC AR build

Title: Re: 6.8 SPC questions
Post by: Pathfinder on May 20, 2010, 07:09:26 PM
^^^^^ What he said!!   ;D

I have a Stag 6.8 upper I run (currently) on a DPMS lower. A more noticeable bark, but if there is more recoil I can't feel it.

Biggest issue is ammo. I was lucky and got some right before the world went nuts and bho got elected. What little ammo I have seen on the shelves locally was Hornady at $40 for 20 rounds. Three out of 4 local stores have not had any for a while. Midway seems to be out, SSA has some - or so they say.

Brass is expensive if you reload - and if you can even find it, but yes, any low-weight .270 bullet should be OK for reloading. IIRC, the round is a .30 Rem necked down to 6.8mm/.270. I have an assortment of Hornady, Speer, and Sierra bullets set aside for when I ever get around to reloading myself. Like KPR mentioned, if you reload, Note that Rem brass takes a large rifle primer, and the SSA brass takes the small! Go figure!!

Title: Re: 6.8 SPC questions
Post by: Fatman on May 20, 2010, 07:21:02 PM
Path, the 6.8 upper fits on a 5.56 lower, yes?  How about the Grendel? I'm guessing yes, probably really close in cartridge size.
Title: Re: 6.8 SPC questions
Post by: tfr270 on May 20, 2010, 07:26:07 PM
Beat me to it Fatman...I was wondering the same thing. Thanks Kilo and Path!That is a nice rifle you have there.
 
Title: Re: 6.8 SPC questions
Post by: Pathfinder on May 20, 2010, 07:30:29 PM
The 6.8 and the Grendel - and Beowolf IIRC work on the 5.56 lower. Oddly enough, so do the bolt-action .50BMG uppers, although obviously not the semi-auto types.

I went with the 6.8 mainly because I was not interested in supporting the litigious and proprietary Grendel.

BTW - mags are generally available, even if the ammo ain't. C-Products makes some nice ones and they're not that expensive either.
Title: Re: 6.8 SPC questions
Post by: kilopaparomeo on May 20, 2010, 07:40:01 PM
Yup, the AR lower has been made into a lot of stuff.  In this pic is a .50 BMG, 5.56, 6.8, .22LR and 9mm.  I've had a 6.5 Grendel in the past but sold it.

(http://i49.tinypic.com/nx28tt.jpg)
Title: Re: 6.8 SPC questions
Post by: alfsauve on May 21, 2010, 07:04:12 AM
Given the 5.56/.223 case the 6.8SPC is a good choice for the AR-15.

However, if you go with an AR-10, then you have a wider field of higher powered cartridges to chose from:  .243, .260, 7mm-08, .308 and .338Fed. 

Just an option to think about.

Of course everyone should have both and AR15 and an AR10 lower, right?

Alf

just working on my second AR-15 build out.  :)
Title: Re: 6.8 SPC questions
Post by: Solus on May 21, 2010, 11:56:05 AM
Since we have this topic going, I'll ask a question I have been considering.

I happen to have an Olympic upper and lower I acquired in the early 90s.  The upper is stripped but the lower seems to have all the parts, but I'm not experienced enough to say it has them all. 

I have wanted to so SOMETHING with it for some time now.

I haven't heard much good about Olympic so my question is:  Should I try to build a 6.8 (or some other variant) on this lower and upper or are they not up to the job?

Thanks.
Title: Re: 6.8 SPC questions
Post by: ericire12 on May 21, 2010, 12:19:23 PM
Yup, the AR lower has been made into a lot of stuff.  In this pic is a .50 BMG, 5.56, 6.8, .22LR and 9mm.  I've had a 6.5 Grendel in the past but sold it.

(http://i49.tinypic.com/nx28tt.jpg)

I hate BillT kilopaparomeo  ;D


*I think at some point you have enough guns.... redistribute.... social justice.... etc etc ;D
Title: Re: 6.8 SPC questions
Post by: Pathfinder on May 21, 2010, 12:19:46 PM
Since we have this topic going, I'll ask a question I have been considering.

I happen to have an Olympic upper and lower I acquired in the early 90s.  The upper is stripped but the lower seems to have all the parts, but I'm not experienced enough to say it has them all. 

I have wanted to so SOMETHING with it for some time now.

I haven't heard much good about Olympic so my question is:  Should I try to build a 6.8 (or some other variant) on this lower and upper or are they not up to the job?

Thanks.

Good question, Solus. I've heard about Oly quality issues, but have no first-hand knowledge of them. My understanding is that the quality issues are in the past, not with current or recent manufacture.

Theoretically, though, you can replace the Oly barrel, bolt assembly and 5.56 magazines with 6.8 parts, and be good to go. That pretty much leaves only the upper receiver housing as a critical Oly part. The rest (stock, forward hand grips, etc.) really don't matter from caliber to caliber. Since you'd be swapping out most of the Oly upper stuff, I think you'd be OK, IMHO.
Title: Re: 6.8 SPC questions
Post by: bafsu92 on May 30, 2010, 10:19:40 AM
I've had no problem getting 6.8 ammo. Go through either SSA or Natchez Shooting Supply. Both have plenty of different options starting around $16 for 20rd boxes.
Title: Re: 6.8 SPC questions
Post by: Combat Diver on June 07, 2010, 12:46:56 PM
The 6.8 SPC has been on my want list since my friend Steve Holland help build that cartridge in 5th SFGA.  I'm just never home long enough to do anything (only been home 3 yrs out of 10.5).  One of his first guns chambered in it was a CZ527.  I'm thinking either a barrel for my TC Contender or building another AR for hunting use.  Here's a photo from 02' on the development of the cartridge.  Notice the barrel twist.
(http://www.hunt101.com/data/500/medium/MVC-005F4.JPG)

Here's Rob Letham and Steve Holland (uniform) with a M4 in 6.8 at Ft Campbell
(http://www.hunt101.com/data/500/medium/6_8_group_L_unkn_rob_letham_steve_holland_and_don_alexander.JPG)

CD
Title: Re: 6.8 SPC questions
Post by: Pathfinder on June 07, 2010, 01:58:22 PM
CD, would that be a custom twist rate? ? ? ?     ;D

Thanks for the history artifacts, those are damned cool!
Title: Re: 6.8 SPC questions
Post by: PegLeg45 on June 07, 2010, 03:41:32 PM
Cool pics and post, CD....glad to see you back on here.
Title: Re: 6.8 SPC questions
Post by: m25operator on June 07, 2010, 08:34:29 PM
Nice, and I will take this opportunity to again, say, accurate rifle shooting, starts with records, the target has good facts, but a record book will have more, including sight settings, wind direction, sun position, wind speed, etc... that will allow you to make 1st round hits in a place you have never been. I expect 100 yard shots will always be on target unless your in a hurricane with a centerfire rifle. But filling in the blanks lets you adjust, for shots further out. Also an iron sighted AR/M4 sighted in at 100/200 yards will shoot 6" low at less than 15 yards, really not a problem unless your shooting head shots, and even then if your on target, will hit the throat in line with the spine.
Title: Re: 6.8 SPC questions
Post by: tfr270 on June 09, 2010, 12:17:58 PM
Thanks CD. There is guy with a Stag 5H for sale. The barrel twist is 1/10. The price is pretty darn good at $750.