Modern Intermediate Calibers 003: The 6.8x43mm Remington SPC

Three 6.8 SPC cartridges and their parent round. Left to right: .30 Remington, 6.8 SPC 115gr Sierra BTHP, 110gr Hornady OTM, XM68GD 90gr soft point.

I’ve written quite a lot about the ballistics one of the first Western competitors to 5.56mm in the new millenium previously, and you can read that by following the link here. The 6.8x43mm Remington SPC was developed in the early 2000s by MSG Steve Holland and civilian US Army Marksmanship Unit gunsmith Cris Murray as a second iteration for the Mk. 12 SPR precision upper receiver for the AR-15. The 6.8 SPC was never adopted by a Western fighting force, but it subsequently became a popular civilian hunting cartridge, and it still features prominently in discussions about next generation military calibers, so let’s take a look at the ballistics of two¬†popular 6.8 SPC loads:
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The XM68GD 90 grain soft point round is one of the lightest 6.8mm SPC rounds there is, at about 15.9 grams (245 grains) per. The 110 grain Hornady load weighs about 17.6 grams (272 grains) in contrast, while the heaviest factory load, the 120gr Hornady SST, weighs about 18.2 grams (281 grains).

Note: All ballistic calculations are done with JBM’s Trajectory calculator, using the ballistic coefficient appropriate to the projectile being modeled, and assuming an AR-15 as a firing platform. Also, keep in mind that there is no single true velocity for a given round; velocity can vary due to a large number of factors, including ambient temperature and chamber dimensions. Instead, I try to use nominal velocity figures that are representative of the capability of the round in question. The velocity figures I use here are educated guesses for the barrel lengths used, based on velocity figures collated from here, here, and here.

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • William Brocius

    Nathaniel another half baked discussion! Obviously a hip shot of research. Nosler purchased Silver State Armory and now supplies a large selection of 6.8mm ammunition. While SSA is referenced within the links, the 85gr and 110gr make, IMHO a far better defensive round to any of the 5.56mm! And out to 400 yards is comparable to the .308 (7.62mm X 51).

    • Dracon1201

      Tis not a discussion, just a sampling like the 5.56 and 7.62×39 articles.

    • Darkpr0

      You could refer to the multi-page discussion of 6.8 SPC previously published on TFB if you wanted a more in-depth discussion into it. I’m sure it has more than enough reading material for you.

    • LOL, getting on me for “a hip shot of research” when you missed the link to the 3700 word article I wrote on 6.8 SPC a year ago!

    • iksnilol

      Problem with specialty rounds such as the super lightweight 85 gr ones are that they aren’t common. Often they have to be reloaded or ordered online.

      That’s like me saying my car is awesome because it uses little gas for me to get to work (on a short straightway). It isn’t really representative of what is there.

  • McThag

    Precision is everything. Grams are a unit of mass, not weight. Grains and ounces are weights. Mass and weight are not entirely interchangeable, and getting this simple distinction wrong can lead one to wonder what else was just “meh close enough”.

    • ostiariusalpha

      Well, here on planet Earth, we have pretty well established conversion rates between grams, grains, and ounces. If I go plinking on the moon the distinction between mass and weight might be relevant, but I don’t see that happening anytime soon.

      • Yeah, ask anybody in a metricated country how much they weigh, and you’ll be waiting a long time for them to give you an answer in Newtons…

    • LilWolfy

      When I’m working with coalition units from Europe, they talk about bullet weight in grams. The guys that hand load in the various sniper communities always refer to bullet weights in grams. They use the metric system.

      You’re confused about something, but I’m not sure what it is. Kilograms and grams are units of measure almost everywhere. I personally prefer grains when reloading, but it is what it is.

  • Fox Hunter

    i like the parent cartridges better, .25 rem, .30 rem. lower pressure, but still good intermediate performance.

  • gunsandrockets

    Just saw for the first time ever a Ruger Ranch Rifle in 6.8mm SPC in a local gun store. Should I buy it?

  • mig1nc

    I hope to see a roundup article at the end of the series with all the charts laid on top of each other by barrel length – Like a 14.5″ barrel chart with all the cartridges, etc…

  • Fox Hunter

    I think the Jordanians or some other middle east country has adopted the 6.8 spc 2.

  • gunsandrockets

    How interesting. According to the information I found, the Hornady 120 grain bullet load in 6.8mm is a near ballistic match for the old .276 Pedersen cartridge with a 125 grain bullet.