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While 300 BLK may be my round of choice, 6.8 SPC was on the scene first (and, according to some, does the job better). But there’s a problem: there aren’t really any polymer magazines on the market that fit the wonder round. Instead of being based on the 5.56 NATO round like 300 BLK, its based off the 30 Remington case. Which means that standard magazines aren’t an option and there haven’t been any really good replacements. Until LWRC let the cat out of the bag about a new project…

A rumor has been going around the internet that Magpul is going to be making some polymer 6.8 SPC magazines, and the reason we heard about it is that LWRC posted some images of a new 6.8 SPC carbine that they’re developing for the military.

The fact that LWRC is making a 6.8 SPC rifle is nothing special, but what is interesting is that it seems to be a joint operation with Magpul for the magazines and Federal / ATK to make some nifty ammunition for the rifle.

Details are still a little scarce, but here’s what Darren (LWRC Executive VP) posted on their forums:

One thing we noticed on high speed video was the crimp groove in the primer caused a bit of erratic ejection when combined with a 5.56 ejection port opening and the angle of the case deflector. This accounted for 2 stoppages in 1000 rounds (stove pipe). The angle of the deflector was changed, the port opening is now tapered from front to back (20% larger at the front), and the ejector was changed slightly. With the gun optimized as it is and with the consistency of the ATK ammunition, you can literally catch brass in a coffee cup.


The six 8 upper is different other than external dimensions. It matches and supports the feed lips for the magpul mag.

So, new magazine, new upper AND lower receiver design, and a new ammunition. We’ll let you know more as information leaks out, but we’re expecting the full details to be available around SHOT 2013. What we do know (including these pictures) comes from LWRC’s forum, which might be a good place to stalk if you’re an LWRC junkie.

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    • WB, according to my conversation with Darren a few months ago, neither the upper nor the lower will be compatible with standard AR15.

      6.8 mags are currently not available in polymer because the polymer is thicker than aluminum and won’t fit a standard magwell. The new mags will require a wider magwell. I assume the upper and the feedramps are designed differently due to a new feed angle on the new mag design.

      I expect this will be a great improvement, but the downside is that it won’t be backward compatible. I am not getting rid of my standard 6.8s and Barrett mags anytime soon.

  1. The crimp grove on a primer pocket fouled up ejection? That’s one vid I wanna see!
    from the photo of the magwell it seems the mags have a stabilization rib on the left side not found on M-4 maggies

  2. At first I was very excited, and now I am concerned. I’ve wanted 6.8 Pmags for a long time to fit in my standard PSA or LMT lower. Still, LWRC makes great guns, and I’ve always been a fan of the 6.8, which can create better energy from a 16″ barrel than the 300 AAC or 6.5 Grendel. The Federal / ATK SOST 5.56 barrier blind ammo is awesome, and I’d love to see that round scaled up for 6.8 duty. If Magpul can pull it off, a magazine compatible with the standard stanag well would be awesome.

    • Magpul has always said that the difficulty in making a P-Mag for 6.8 is that the size of the AR15 magazine well would require the polymer to be far too thin to be at all durable.

      Judging by the floorplate shown above, it looks like nothing has really changed on Magpul’s end, LWRC just made the magwell bigger.

  3. I don’t understand why anyone would get 6.8 SPC over 6.5 Grendel if you want an obscure almost dead cartridge.

    • I’ve been wondering that myself. The 6.5 and 6.8 may shoot flatter and hit harder than the 5.56, but who can afford to modify their gun and replace their magazines, and *then* spend more than $1 per round practicing? Not me.

      Tens of thousands of our nation’s dead enemies can’t be wrong: the 5.56 already offers sufficient lethality at reasonable ranges. And if one round doesn’t quite get the job done for $0.25 to $0.50, you can always shoot twice.

      • If you think the 6.8 is dead… well, you’re dead wrong. They (G and 6.8) both have very strong backing and with good reason. With Fed and Tulammo hopefully jumping aboard soon. Oh btw, I have nothing against The G, especially since it’s like apples and oranges.

        The 5.56 is fine, but IMO the 6.8/6.5 is finer. A buck a round? Your google-fu is off today. You can find a good deal of 6.8 ammo for under a buck. Reload? Even cheaper. Don’t reload? Sell your brass. Many dead hogs, bucks, elk, ‘yotes, and other critters can R.I.P thanks to the 6.8.

        • Absolutely. The 6.8 would also be my top choice for a military CQB round, and it also allows medium game hunting where the .22 calibers are not legal. The 6.8 has a lot going for it.

  4. “(and, according to some, does the job better)”

    You are a straight up idiot if you say 300 BLK is in any shape or form better than 6.8 SPC. Look at 300 BLK 125 GR accuptip. 2215 FPS, 1362 ft lbs. 6.8 SPC SSA 115gr OTM 2575, 1693 ft lbs.

    • Woah Woah Woah… The .300 Bummed out has it’s attributes. I’m not trying to start an AR caliber war… I swear!

    • Wilson Combat 2700 FPS from a 16″ barrel for 1780 FPE, Silver State Armory Berger 140 grain VLD at 2400 + FPS for 1800+ FPE, also out of a 16″ barrel.

      • What cartridge/ bullet weight was for the first set of data? It can’t be the .300 B.O. or the 7.62x40WT. Is it 6.8, 110-115 gr?
        If so, don’t forget about the 100 grain stuff and down. There’s something about 85grainers @ +3100 FPS that makes the heart sing.

    • apples and oranges.

      the 300 blackout was never designed to surpass the performance of the 6.8. different cartridges for different purposes.

      give me a 300 blackout for a SBR with a suppressor. Give me a 6.8 for a designated marksman rifle.

      • This.

        .300 BLK was basically designed to beat subguns and overly-shortened AR’s. It does this well.

        6.8 SPC is more of a mid-range DMR round.

        As for actual distance accuracy, I’d go with .338 LM and/or .50 BMG.

        • The 6.8 is also designed for short barrels. 12″ barrels retain plenty of velocity. Enough to be deadly and accurate @ +300 yards, suppressed.

          As far as suppressed, people are using the 1 in 7 barrels with 200 gr bullets. Though, IMO, the .300 still beats the 6.8 in this category.

        • The 300 blackout is far superior in a suppressed setting. hands down. Suppressed 300 blackout ARs are supposedly more quiet than a MP5SD.

          Sure, the 6.8 might be very effective in a SBR, though it wasnt designed for one. It was designed as a longer ranged round with more kinetic energy than the 5.56.

          The 6.8 is also damned loud. Suppressors work rather abysmally with them.

  5. I use standard 5.56 mags for my 6.8spc and it works flawlessly. there’s no need to buy 6.8 specific mags, I think that’s just a rip off.

    • I’ll bet you can’t load a full 30 rounds in them, though, can you? Or run them reliably suppressed? 😉 It’s not a rip-off. Far from it.

  6. The 6.8 wasn’t designed for SBRs? Wrong.

    “The 6.8 mm Remington SPC was designed to perform better in short barreled CQB rifles after diminished performance from the 5.56 NATO when the AR15 was changed from the rifle configuration to the current M4 carbine. The 6.8 SPC delivers 44% more energy than the 5.56 mm NATO (M4 configuration) at 100–300 metres (330–980 ft).”

    Out of shorties, the 6.8 retains plenty of it’s velocity and KE compared to 16″ barrels.

    As far as, loud I’ve never noticed too much difference. Can you give me a muzzle break/ FH that was used? As far as suppress, seems weird a good number of people run suppressed and enjoy it so much. Also, as I’ve said before, the 1 in 7 twist with 200grainers seems to be PLENTY quiet.

  7. These comments are funny, If the 300 bummed out, or the 6.5 gremlin were all that then they would be the ones getting the support and contracts from govt’s and major manufacturers, enough said, lol.

  8. I have a friend that has a DPMS in the 6.8 and I have never looked at it closely but I read somewhere that the 6.8 upper will work with the 5.56 lower. Is this true, or did someone get this info. wrong. I wanted a 6.8 upper to go on my sig M400 5.56 so I could use it deer hunting in southern Iowa. They have a few counties that allow hi power rifles to hunt deer with down there. Not anywhere else in Iowa though…So does the 6.8 upper work with the 5.56 lower is my question….

    • The new Six8 upper will not work with standard 5.56MM lowers, per Darren at LWRC. The weapon system is proprietary and made to contract specifications. It’s optimized exclusively for the 6.8 SPC. The feed characteristics are different, too, in order to accommodate the new magazine which was developed to solve the problems of improper stacking of the rounds and stacking tolerances.

      If you want a quality 6.8 upper that will work with standard AR-15 lowers, there are plenty to choose from.

    • The answer is YES! You can use a 5.56 lower with any other (not LWRC) upper! I have a YHM multi-caliber marked lower with a Rock River Arms 6.8 upper.

    • I Have a DPMS 6.8 upper on a 5.56 Rock River lower and it works great. I use PMI mags with 130 gr sp bullets. you can use 5.56 mags for 110 gr bullets but can only load about 5 rd or it starts jamming in the mag because of the tapered cases on the 6.8 spc.

  9. I purchased 5 precision reflex inc magazines for my 6.8 and 3out of the 5 jam has any one had the same experience? its jp rifle upper on a jd machine lower

    • PRI needs to get rid of the vertical rib at the top of the mag, the rim of the case catches on it and causes the bolt to slow down. I had 12 new PRI mags
      that all had this same problem. They improved a little with wear but you can still see the bolt “stutter” as it moves forward.

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