Original Post

From what I've been able to gleam, there isn't much information on the platform used to trial the 6.8 with 5th sfg and those who claim to know are apparently reaching because those who know can't say anything??? (that's what I ready anyway). There's a tiny bit of information from this older thread (https://www.ar15.com/forums/ar-15/Status_on_6_8_SPC_use_in_combat_and_AMMO_availability_____/118-222610/) but the only mention of a platform is "crates of them having been seen while being sent off to war". Because of the time frame this round was being developed and tested a long with the group doing the testing also coinciding with reports (one mentioning a 16" MK12 variant "Recce") of ballistic testing referencing velocities and barrel lengths it seems resonable that the Mod 0 was the platform utilized. Possibly being the Mod H before the H was a thing. Of course, I could be way off on this for I am just a dude who does lots of reading on the internet.

Thoughts?


Some reports I've been combing through:
{Update: 6.8x43mm SPC SPECOPS Cartridge in Trouble?}
{6.8 Remington SPC - NDIA Small Arms Symposium}
{Wound Ballistics Terminal Performance Facts}



Updated 2/27/2024

Impressively, this post has brought out some very knowledgeable folks regarding this topic so I wanted to provide direction to  that information here for new comers (we all know what it's like to search threads for info). This information is more directed at the program itself with the weapons platforms. There is other great information in this thread as well regarding other aspects of the 6.8 round. Now we just need to get Steve Holland on here to give us a full break down

50cal
Posts (Page 1): #2, 6, 10, 20
(Page 2): #7

WillMunny
Posts (Page 2): #3, 9, 12

Combat_Diver
Posts (Page 2): #22-24


Members from closed post
https://www.ar15.com/forums/ar-15/6-8-spc-Development-w-5th-SFG-and-USSOCOM-MK12-Variant-/123-785202/

Paradude54
Posts #1, 3

In addition to the information above, check out Chris Bartacci's book, America's Rifle, for some in-depth information (I'll just post a 10,000 foot view). As most of you probably know, he is a wealth of information when it comes to the Black Rifle. In summation, he says prototype weapons were mainly tested with 12.5" and 16.5" barrels in initial prototypes of MK12 Navy Recce and CQBR configurations with PRI and ARMS components (amongst others). It also appears there was even an 18.5" MK12 prototype but I haven't been able to find much of any information on that. I'm guessing it didn't have a substantial advantage over the 16.5" version. Again, check out Chris' book, it goes into far more detail.



Pictures

Purported 5th SFG with 12” Barretts (Courtesy: WillMunny)


L-unk, Rob Leatham, Steve Holland and Don Alexander @ Campbell 02/03 (Courtesy: Combat_Diver)





Family of Special Purpose Cartridges (SPC) (Pulled from 68forums posted by Mr. Holland)

Steve Holland was the driving force behind the 6.8.  

I don’t remember much more, it was a busy time for us.

18Z50….TF Dagger alumni

Steve Holland came to Barrett a few times with an upper built by some of the armourers at 5th Group. He had some ammo made by someone at Campbell. The parent cartridge was the 30 Remington.
Holland came down to see about Barrett producing some uppers. Remington finally came through with the first version of the ammo.

After quite a bit of trial and error. And chamber and throat changes, we made a bunch of uppers that SF ended up taking to the Middle East to use.

The Marine Corps wanted a bunch of 12.5" barreled uppers and dedicated 6.8 suppressors. We made around 150 of the 12.5" barreled uppers and titanium suppressors for each upper. Pretty sure those uppers were slated for FAST Teams. Pretty sure. It's been awhile.

After the growing interest in the 6.8, we started with the M468 rifle.
We built just a few 20" barreled uppers for the Marines . They wanted a 6.8 DMR styled upper to test. I think we only built 10 or 15 of those uppers.

I've had a 6.8 since then. Have 3 of them currently.

Cool details! You’ve got my attention. Any info on the upper brought to Barrett by Holland?

What did the uppers you guys built used in middle east comprise of?

How about the 12.5?

Was the 20” DMR version built with the A.R.M.S. 59?

So many questions! Lol

Big fan of 6.8SPC

My REC7 sports an AAC M42K with serial number M468. Always thought that was really neat.

Carriers were off the shelf Colt or LMT carriers and bolts. Bolt faces were opened up to accept the 6.8 diameter.
Later when the gas piston rifles were brought out, the gas system and gas block were proprietary.
The M468 gas block had the threads for attaching the suppressor machined into the front of the gas block.
The muzzle device was a brake of Barrett design with the boss for locating the suppressor and keeping it concentric to the bore.
The suppressor had 2 points of keeping it located to the bore. The threads on the gas block and the boss that went up into the suppressor about 3 inches or so. May have been a little less.
The rifles that went out had a thread protector on the suppressor mount threads on the gas block.

6.8 SPC is a great round

Any idea what Holland brought to you guys to look at initially?

Thanks for the info on the uppers. Seems the ARMS rails came after with the MURG program trials (or something like that).

Were the carriers in the DI M468 LMT with LMT enhanced bolts?

I like my home built 6.8:
Attached File


But the advent of the improved 5.56 GI ammo, like the Mk262, took away the perceived need for a general purpose caliber change.

When the M468 was discontinued and the Rec7 line started,  Barrett started making their own piston carrier on a 5th axis CNC. The bolt was made at Barrett also.

Barrels on the M468 and Rec7's were E.R. Shaw barrels for a long time.

Oooo, that Elcan sits pretty on there. I bet it’s a nice combo. MK262 is some awesome ammo. Because the 115 gr at 2600+ are so close in performance it makes me want to rebarrel the H to the 6.8. I’ll definitely go with this chambering, I’m just deciding on the host. Seems 16” and 12.5” are quite popular due to their performance not differing much.

So slightly off topic Q for the guys that have answered so far.

What are your thoughts of 6.8 now?  I wouldn't say it's a dying round, but certainly not as popular as 15 years ago.

After 5.56 I tried 300 BLK, then 300 Ham'r, then 458 SOCOM and 450 BM, and in the last year tried 6.8 SPC.  I'm a fan, and believe it is probably the best overall cartridge for the AR15 platform.  I'll qualify that with the statement that I see the AR15 platform as a 300 yard firearm, that you only stretch to 400 yards in a pinch.  I won't sacrifice performance close in to try and gain more beyond 300 yards.  You can't argue the knock down power of 458 SOCOM or 450 BM inside 125 yards.  The 300 Ham'r is an excellent deer/hog/Self Defense round out to 200 yards.  Overall however, I think the 6.8 SPC is the best overall compromise. YMMV

I was a little slow to embrace it because of all the bad data floating around with SPC I vs SPC II, and Hodgdon reloading data showing performance for a 24" barrel that is in line with what I actually get with a 16" barrel.  The misinformation makes it hard to know what it really does without trying it yourself.  Now that I have, I'm a fan.  I also like the LWRC receivers that work in conjunction with the 30 round pmags.

What 16” 6.8 barrel you running?

My 16" barrel is an LWRC factory rifle.  I have ARP/Blackstone barrels in 10.5" and 12.5" and have thought about adding one of their 16" barrels to another receiver set, but haven't done it yet.

just got into 6.8 spc myself.  well, I bought a YHM barrel a few years ago and just got around to finishing it off in the last few months.  

almost went 300HAMR but when I tried to buy a 10.5" barrel Wilson's sales geeks said "we only sell to FFL" so fuck that.  

just took delivery of some pp ammo today, heading to the range for a two days in a row range fun week.

the history on this really interests me.  

I think it will always be available, enough hunters in "can't hunt with .22 rifles" locations are driving ammo sales.  unfortunately all I can find on the shelves are the $1.50/rd Hornady hunting loads.  no fmj.  going to have to keep placing orders with sgammo for a while until I start reloading again.  

there will be a 10.5" barrel at some point - I got into 6.8 spc for its performance out of shorter barrels.  the bag under the workbench has a 300blk takedown Dolos here at work, I want that to be a 6.8 spc soon.

I don’t care how popular it is

I have tons of brass and 270 bullets are easy to find

what was the intended bullet weight when the 6.8 was under development? is there a somewhat regularly available factory ammo that would be recommended for SD/HD use, i seem to remember that the 95gr was very popular when it hit the commercial market, however all i can seem to find is 110gr -120gr factory loadings now

I believe original development centered around the 110 and 115 gr bullets (see below for a statement made by Mr. Holland). Currently, seems the xm68gd loading (90gr gold dot) is quite popular. It was developed for oversees contracts in conjunction with the LWRC UCIW platform.

“I worked with “___” at Sierra Bullets to develop the 115gr Cave bullet, with Dave Emary at Hornady for the 110gr AMAX minus polymer tip and closed in to meet legality of Land Warfare and Pete Forras (RIP) to develop the powders at Ramshot.”

Pete Forras was an asshole of the highest order. He worked at Barrett for a while doing load development for the 6.8
He was the unsafest person at a loading bench I had ever seen.  He would cook up the craziest duplex powder loads ever. Blending pistol and rifle powders and asking me to fire it while telling me they were something else.
I pulled down  single rounds of his "loads" and found the stupidest mixtures. When I refused to fire them, he took it up to Ronnie Barrett as me refusing to do my job and Pete wanted me fired.
Ronnie took my side and told Pete to fire his own loaded rounds.
He blew up a few 6.8 rifles. And destroyed a few of our suppressors also.

Hate to speak ill of the dead, but Pete was a weapons grade asshole. That is also the reason he got let go at CorBon.

Buy 90 grain XM68GD or the Federal 90 grain Fusion if you can find it.
I bought a lot of the Federal white box XM68GD when Palmetto State Armory was blowing it out at $7.95 per 20rd box years ago. I'm still sitting on a bit over 2500 rds of it.

The 110g V Max load is a good one also I buy the projectiles for reloading when I find the 100 ct boxes at decent prices.

@50cal

thanks for the info.  i got out of 6.8 a few years ago when the XM68GD was that cheap and wish i'd have stacked up.  i'm building a new 6.8 now and just trying to find what ammo i should lean towards.  it looks like 110vmax loaded ammo is pretty easy to come by.

thanks

T

Glad to help.
I've been buying Hornady 110 g FMJ projectiles also. I catch them on sale at Academy periodically.

You wanna let that XM68 go anytime let me know.
they don't make it anymore from what I've found.

Appreciate the offer. Keeping this ammo as it's really good stuff. Great accuracy from all 3 of my 6.8's.
I've been picking up Barrett 30rd mags off of gunbroker also at decent prices.
Paid "19 each for 10 of them 2 seperate times during Christmas sales on the Barrett website.   Ow that they discontinued the 6.8 offerings, I pick up the stainless 6.8 30rders when I find them.

I wish Prvi would do another run of 6.8 ammo. I'm getting a bit low on it as it is good stuff also.

Any experience with S&B 110 FMJ ammo?

How do the PRI 6.8 and Barrett 6.8 mags compare?

Can't help but comment as I also am a fan of the 6.8 SPC with two AR-P 12.5 barrelled and one RRA 16" all running suppressed.  As far as magazines I have standardized on PRI's.  In regards to ammunition I reload and have standardized on Barnes 95 grain TTSX's over LT-32 powder.

I have a bit of the S&B 110g 6.8. Good shooting ammo. Through each of my rifles it gives pretty good accuracy. I  consistently hit a 8"x13" steel plate at 300 yds with it. Haven't grouped it though.

The Barrett and PRI mags are on par with each other. I bought quite a few PRI mags when they were the only game in town for dedicated 6.8 mags.
When Barrett started with their 25rd then 30 rd mags, I bought a lot of them when I find them. Keep an eye on the EE here and gunbroker.  I've scored around 12 - 13 of them on gunbroker at around $14-$15 each which is a great price on them.

@Capt_Jerry Do you notice any pressure issues between the ARP and RRA barrel considering the differences in chambers and rifling? Have you checked the velocity differences between the 2? I’ve been eyeballing the RRA.

18"
16"
14.5"
12.5"
all ARP with wylde chambers
I haD 2 REC7's but traded them for SCAR17s

@50cal
No to derail the thread but…
Sgammo has the 110 FMJ and bthp prvi in stock for $1/round… as well as the S&b 110gr FMJ for the same price.  Any recommendation on any of those? Kind thinking the 110gr bthp as a general range/pig round.  Thoughts?

got 4 boxes of the pp today from sgammo, going to buy more.  

first ~6 rounds were failure to feed - didn't jam, just didn't strip it out of the magazine.  not sure why.  after manually cycling the rifle, the rest of the magazine was perfect.  

C-Products magazine.

previous 2 magazines were the Hornady Black 110gr.  no function issues at all.

6.5G > 6.8SPC

I would go with the s&b, more accurate in the 110 fmj, 115 grain hpbt and 110 grain pts bullet.  The ppu I have shot through my 6.8 has been ok accuracy wise but pretty weak ejection compared to the s&b when running the gas block on the same setting.  The ppu uses large rifle primers also, s&b has small rifle primers.  You could sell the s&b brass to recoup some of the cost if you don’t reload, it is the best 6.8 brass on the market.

I really like the Prvi. The brass is really good for reloading. If you don't reload, you can sell the brass here on the EE for 40-50 cents a piece.
The S&B is good ammo also. I just like the Prvi better for its accuracy consistancy.

There's always one.

Attached File


Since Holland has been mentioned here several times, I thought you readers might enjoy this story. Years ago while he was on active duty, he was an attendee at a NDIA convention in New Mexico where this early robot machine gun was demonstrated. While it was firing, a crowd of about 50 folks including Steve and I were standing close behind it.  As it fired, it became out of control and started to rotate back towards the crowd, as many began backing away quickly from the obvious lethal danger, Steve rushed forward and twisted the belt apart; and luckily the remaining belted rounds left in the gun depleted in a second or two before the self-traversing tractor fully turned towards us. Holland saved some lives that day...

Wow. Cool story.

Steve is a regular guest on Karl Erickson's TR Live livestream on Tuesday nights. He told this story once. He also gets into the 6.8 SPC and the SPR program from time to time (touchy subject for him). He's a national treasure.

I bought some of the Federal ammo from PSA, to use in my PSA carbine.  Killed buck about three years ago.  

IIRC, the Jordanian Army issued a 6.8 rifle and ammo, at least to some units.   Any idea of it's still used?

I remember wanting to get into 6.8 when I first started getting into AR's, and reading about 6.8 compared to .300blk. Seems like neither were that well established at the time, and 6.8 looked like a better cartridge. I think .300 has won the popularity contest, and I just recently go into it since it shares components with 5.56 and .308.

I assume the trials you are talking about were not recent?

Very early 2000’s.

Anybody know the report or article this image was pulled from? I saved it from a thread awhile back and I didn’t even realize what I was looking at at the time besides a Mod 0. It is a 6.8 SPR MK12 prototype. Reverse image search just brings up the archived thread I found it on here at ARFCOM. Even googling the text in the image just brings up random sites.

RatWorx was the local 6.8 builder after AWB sunsetted, and met them at my local range.   They built a nice 18" rifle for me

I really like it.   I handload 110gr amax.    Was never super accurate, but always reliable.

wut

I got into the 6.8 way late but I think it's a great round for the Aar platform.

OP there is a forum dedicated to that round that is worth a quick google search. Lots of info and people willing to share knowledge over there.

great resource but the total aggregate traffic there is 1/10 of arfcomm threads that say "6.8 spc" on them...

another 5 rounds today of the fmj - perfect function again.  

posting another reply here to bump it and get more history...  crowdsourcing this kind of history gets really interesting.

going to get the reloading bench going asap.  this thing is fun to shoot and ammo is expensive.  so is reloading but then at least I get to have fun reloading and also shooting...

https://smallarmssolutions.com/store/p6/America's_Rifle.html