@failure Chris is a wealth of knowledge. I’ll have to check it out. Thanks!

Thank you for the info. 68forums is a great place for info on the round itself (I’ve gathered a lot there), this is more about the platforms used in the program utilized for the development of this round. There is some info about that over there but there’s not a ton of traffic on the forum. Mr. Holland made a few posts over there a few years ago but hasn’t logged in for quite some time.

Glad this post got moved here! For AR-15 shooters and cloners of a certain age, the development of the 6.8 SPC cartridge in the 2002 timeframe was a huge deal. It was still pretty early Internet days, and a lot of the information about the round showed up first in the tactical gun magazines. (Remember when SureFire had a glossy tactical Recoil-like magazine?).  The 6.8 was a big .mil story for about a year or so, and then sort of  faded away after the MK 262 came out. Interest continued on mostly with a small group of hunters and cloners, but it wasn’t ever the same.

AFAIK the only book that really discusses the topic is the book someone else just linked to: Bartocci’s BLACK RIFLE II. It’s an excellent book and his brief chapter on the 6.8 SPC is the best (only?) resource out there. He talks briefly through the issues and the development  – SF troops were concerned about lack of knockdown power of their 556 greentip ammo- so members of 5th SFG group and the AMU and Remington put together what became the 6.8 SPC.

Like the OP says, it would be great if some of the folks involved in the development process would talk more about it. I had a couple of contacts in SF a few years after the.mil 6.8 went away and I was always surprised that no one would talk much about it. I was given some info about the guns themselves: initial uppers were built in house by the AMU using mostly PRI components ( PRI was a go-to supplier at the time as they were also building the MK12 MOD 0 SPRs then), then Barrett produced  prototypes and then the M468 and a number of them were used (both 12” and 16” bbls), and I was told that later some LWRC M6A2s were procured COTS as well. (I had a picture of a stack of  5th SFG troopers training in front of a Hesco barrier with Barrett M468 12” uppers-will try to dig it out tonight.)

IMO the 6.8 SPC isn't just an interesting historical topic by itself, it was also a broadly influential program in that it:
1.) highlighted the degree to which US SOCOM was increasingly willing to pursue new ammunition innovations. That’s still happening today -300 BLK, 6mm ARC, 338 LM, etc…
2.) reignited the “556 is too small” debate that eventually brought us the Sig MCX Spear / XM7 some 20 years later…

I've always said if someone else was buying my ammo I'd have a 6.8 for sure. It seems like it was a bit better in the mags and bolt department than the Grendel. Too bad Hornady wasn't involved from the get go instead of Remington we might have gotten a good round

I'd forgotten/didn't know that was Steve. Neat. The killer robot story was definitely up there in NDIA lore... along with Seberger once demonstrating sonic crack by firing directly upwards.  :D

I'm far from "involved" in anything 6.8SPC development-related, so don't want to come across like I had anything to do with it, other than showing up very early to the party, but since this is a cool thread, and I was adjacent to it in the early days, an anecdote:

I'd wanted to do some suppressor development back when 6.8SPC was only just whispered about, and wasn't available to mortals.

Schmoozed a bit with Army folks I knew, talked to Remington, cold-emailed Holland, reached out to the Special Operations RDT&E for 5th SFG(A), chatted with Ronnie Barrett, and some other folks back in Sept/Oct of 2003 in order to get some ammo and guns. I eventually wound up being allowed to order some cases of pre-production ammo Remington had made for military testing but otherwise wasn't able to sell. Nice, but couldn't do silencer testing with no gun chambered for it.

So, on my pretty-please request, Remington made up the first two 6.8SPC short action 700 bolt guns ever in their Custom Shop. One for me, one for them. (An assist credit here goes to a friend, but I'm not sure if should name rn.)

I got mine shortly before SHOT Show, and figured I'd ride the booth-buzz and see what conversations that started... made a little display, exhibited the system. Sprinkled some 6.8SPC brass and empty Remington boxes around the rifle and its 6.8SPC-engraved silencer's podium.

...which souvenir-hunters promptly stole every piece of the brass from my display throughout the show. Some people were at least nice enough to ask "Can I have a piece of brass? Or an empty box?" But folks were definitely interested in that caliber that year.

Not sure where that rifle wound up. Maybe Smith & Wesson has it now. Shrug. Lost track of it. Probably some Remington collector/6.8SPC fan would find it interesting.

@WillMunny I’m glad this thread has caught the attention of those who have had first hand or near first hand experience with this round’s development. Very cool to hear from y’all on the topic.

With the info you received about PRI parts initially being used were they essentially the twin of the Mod 0 (I haven’t gotten my hands on Bartocci’s book yet) as pictured on page one of this thread? Really drives my curiosity to see if they ever slapped a 16” barrel in one of those PRI rails. Almost seems fitting for a Holland build, lol.

Man, I look forward to those pics with the 12” M468.

Thanks for sharing!

Wish I had taken some pics when we were testing the Marine Corps 12.5" uppers with our suppressors.
I'm sure there are pics on the Barrett server. We did a bunch of high speed photography with it also.

There are a lot of really cool high speed camera clips at Barrett. We did a lot with each of the guns we produced.

Ooooo, I bet that footage is cool.

Bartocci says 6.8 SPC was tested in both the MK12 format and the M4 format. But he also says more specifically that the initial MK12 6.8 prototypes were actually based off the Navy’s 16 inch “recce rifle” program concept, not the Mod 0.  And he includes pictures of a 16” PRI recce rifle (essentially a Holland but with the carbine-length PRI forend and a barrel-mounted Mod 0 front sight), a Mod 0 in 6.8, a prototype Barrett M468, and a production Barrett M468.

@WillMunny
Thank you for the information. That is incredibly helpful and very interesting indeed. I need to order up that book. Did the prototype M468 pretty much look like the production M468?

I was really getting into three gun competition in the early 2000s and spent a ton of time and money working up a major power factor 6.8 AR. In the early days of USPSA, multi gun, they still had power factor scoring, just like handgun matches.

Of course, within a year or two they dropped power factor scoring in multi gun, so the 6.8 was useless, and expensive. Oh well, it was kind of a fun build.

The prototype M468 looks generally like the production M468 (same midlength ARMS SIR handguard) with 3 differences:
1.) the prototype barrel has a heavier profile, & it looks to be stainless.
2.) the barrel mounted folding front sight is not Barrett’s, it’s PRI’s
3.) prototype doesn’t use Barrett’s proprietary muzzle brake, it uses the MK 12’s OPS Inc brake

Feel free to PM me & I can text you a couple of photos to post (I won't set up another image hosting account in 2024 on principle. It’s beyond annoying to me that this site has the same forum architecture that it had when I first started coming here in 2001!)

Will

I love 6.8 SPC ll but the cost and availability suck. I was going to ditch my 7.62NATO ARs after reading Dr. Roberts report on 6.8x43mm. I built a couple of uppers, bought mags and a good supply of ammo and then things went south on the price and availability of ammo. The ammo situation has gotten better but the price sucks and I still have a nice stash.

I would agree. The forum is quite antiquated and needs some modern features. I for one would like to be able to post pictures separate of another website and have the ability to search threads for key words that have 100’s to 1000’s of pages. It would help mitigate duplicate questions being asked multiple times. I mean, I’m not sure who has time to read every post in a 1000+ page thread for a single answer they may need.

Boutique ar calibers aren’t cheap.  6.5 grendel ammo pricing is the same only difference is a few more options. The 6.8 is a great round, my only regret is not building one sooner.  I started the build in 2019 and finished it in 2020. I feel like I missed the golden age of 6.8 ammo.  Psa prices on xm68gd was killer from what I’ve read.

Honestly I think the round makes even more sense now with the push to shorter and shorter barrels.  I'm set on ammo and components, so it'll be staying in my collection for some time.

6.8 SPC is objectively more effective, deployable and reliable when all of those are considered than the new whiz-bang kids with their 24" barrel velocity claims- and the next wave of whiz-bang cartridges to replace the last and so on.

My 1" out of the box Daniel Defense barrels don't hurt either.

The 6.8 really is an impressive cartridge with the right chamber (too bad Remington screwed that up). If the correct chamber prints would have been saami’d I believe it would be far more main stream than even the 300 BO.

I hear that pretty consistently about the DD barrels. Currently, they are the only one of their barrel build type. RRA is a close second with their option of CL which are made by Wilson.

I use Daniel Defense barrels in all my build ups. I did find a Yankee Hill 6.8 on sale about 2 years ago. It is fluted and nitride. Built it up on an Adams Arms piston kit I've had for years. I like that set up a lot.

No you dit ant!

@cebiNg

I've known Steve Holland since GW1 and we would discuss guns in 5th.  He was my Sniper Instructor there at Campbell in 94'.  Later we both work up at Group staff around 97-98', him in S-5 and me in the S-3.  During that time worked with him on the SPR (later Mk12) and 25mm M82 Barrett (XM109 ).  I PCS'd to 1/10th SFGA in Germany when he worked on the 6.8 SPC.  So I wasn't there when developed.  However, He did send me some pictures of him working up the 6.8 using a rebarrelled CZ 527 (he asked me to locate some rings from Germany) and some range pics at Campbell with the 6.8 SPC.  I'll post the pics later.

Rob Leatham firing the 6.8 at Campbell 02/03 timeframe
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L-unk, Rob Leatham, Steve Holland and Don Alexander
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Check out the velocities during devlopment.

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I just remebered all the ticks!

16” carbines

1-4x LPVO scopes 1/2moa clicks

both require 17-19 clicks elevation to clang 400yard steel plates

both CLANG them about equally hard ( much louder than 5.56nato)

the 6.8 feels much smoother, the 6.5G feeds clunky, with that funky case shape

i only notice it when shooting side by side

I’m on my 3rd 6.8spc barrel ( rra, woa, wilson combat LW) but on my first 6.5G

in other words, more experience in handloading and shooting the 6.8SPC



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My only 6.8 upper is a Cardinal Armory/Ko-Tonics. The most accurate chrome lined ARs I've ever had. When I bought that upper I also bought some Silver States Armory 90 Varm ammo. I wish I'd have bought a couple thousand rounds of that stuff. It was loaded hot and is one of the most effective rounds I've ever used for coyote hunting.


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@Combat_Diver

These are all great to see. The one with the ARMS rail sure stands out. Those targets and velocities are pretty impressive.

The XM109 was a fun project. First shots out of the first prototype made me see stars. I almost went out. After engineering ran the numbers for felt recoil, they came up with a hair over 100ft lbs of felt recoil.
Numerous modifications got it down below the 75 lb mandated by the Army.

100 ft lbs!? My goodness that is a lot of force on the shoulder. Sounds like an adrenaline rush. This platform still in use today?

No. It never went past the 1st 25 units we built for testing. The Army probably has them in storage at Anniston or Bluegrass Arsenal.
ATK sent us a bunch of practice rounds. The projectile was all aluminum with a  copper or brass driving band.
The ammo probably isn't even produced.

Combat Diver, thanks for the great pics!

Looks like Rob has the 12” Barrett in the 1st pic and a longer (16” or 18”?) rifle with a rifle-length PRI rail in the 2nd? Interesting…

Almost looks like the PRI variant prototype recce with the folding fsp.

Thanks for the stories, Combat Diver.  I've not seen Don in quite a few years.  Brought back some fun memories of him.

Thanks for sharing this info.  I used to dream of CZ offering the 527 in 6.8.  I think it would be the perfect lightweight deer/coyote woods gun.

The ARMS scope mount in this pic is the #19 with #21 rings, anybody know the centerline height of this combination? A brief search of the ARMS website doesn’t give this info like it does on their other scope mounts.

What are you talking about?

My guess is 6 ARC, 22 ARC, etc. I believe Hornady is claiming 22-250 “like” velocities with the 22 ARC. I guess we’ll see when end user field reports come in.

After browsing the forums at 68forums the brass used for actual loads shipped in the last 20 years has an interesting history.  

anyone have direct experience with where the components were originally sourced back in the day?

I have about 100 once fired recent production Hornady brass, about 40 ppu, and about 40 s&b.

getting set up for reloading for the first time in 20 plus years.  

the history of these rifles and the cartridges in very interesting!

I was just stirring the shit pot. They were designed for different purposes. The 6.8 is geared more towards CQB and performs better (in terms of velocity and energy, all else being equal) out of shorter barrels. The 6.5 is geared more towards long range. But ballistic coefficients and sectional density don’t lie, and the 6.5 wins in both.

Yeah, the debate continues. lol. It seems the 6.8 encompassed the best compromises for them at the time. Holland developed a "family" of SPC cartridge during the testing. The rebated rim variant caught my attention. Seems they figured out the inherent issues with this design way before Nosler did with the 22 Nosler. I'm guessing Nosler knew but went ahead anyway (complete speculation).

I have about 2k of SSA brass and about 2k once fired Federal brass and about 1k of new SSA

Can you shed some light on the ill-fated suppressor concept, @50cal ?  From my outside perspective, it looks like someone thought they had a brilliant idea to mount it directly to the gas block, because then there wouldn't be the need for the OPS Inc. Collar, but then realized that the "brilliant" idea wasn't brilliant at all, and effed up the accuracy, because it un-free floated the free floated barrel (kinda).  

The can that mounted to the gas block and had a boss on the muzzle brake worked really well. I only fired it in that configuration on the 100m indoor range.
We only did them for the Army and Marine Corps shorter barreled uppers. We sold some to civilians. Not a lot though.

They are a cool suppressor in the era of OTB design. Don’t see them often but once in a blue moon they pop up.

You guys are really making me miss the days when I was in 5th Group and the brief time that I was at Barrett. I was in 5th Group pre 9/11 and Barrett in 2002 when Steve used to show up with various versions of a new cartridge. I knew him when I was in SF, or to be more accurate, I knew him in passing. At the time I don’t think that he knew me from Adam though. But through listening to what he had to say I built a Mk.12, Mod.0 some time and love the thing. He’s not terribly fond of either PRI or Silver State Armory though. If you want to find him, he joins Karl on the Tactical Rifleman YT livestream on Tuesday nights.

Did you build a MK12 in 556?

Yes, it was a way to research it at the same time and then after it was finished I found Steve again. I caught a little hell about using PRI, not that it’s wrong, just that he hates the company. I don’t know all of the details on that one, I think that it may be a lack of recognition by them, but that’s a guess and I don’t want to claim to speak for Steve. I don’t believe that he has a Mk.12 for just that reason, but I could be wrong on that account.

MK12 is a great platform. I guess if he wanted one that wasn’t PRI he’d have to go Mod 1 or H with the KAC URX, lol.

@Paradude54 IM sent. I guess we worked together. I was at Barrett from Feb 1992 until late 2004.