Sunday, April 5, 2015

An In-Depth Analysis of the 6.8 mm SPC (Updated)

The Firearms Blog has an in-depth review of the performance of the 6.8 mm SPC--a .270 caliber round designed for use in the AR. There is quite the debate in the comments regarding the author's conclusions. The basic contention in the debate was the purpose of the cartridge. The author, Nathaniel F., maintains that the round was developed for medium-to-long range precision shooting, at which it is pretty much a failure. However, a large number of the commentators contend that the 6.8 SPC was developed with the purpose of increasing lethality at short to medium ranges, and does a very good job in that regard (as exemplified by the round's popularity in hog hunting).

I don't know enough about the cartridge to comment on its performance. However, in doing some quick research of information on the internet, I could not find any mention of it being developed as a long-range cartridge other than Nathaniel F.'s article, whereas I found several sources that mentioned it having been developed for the shorter combat ranges of out to 300 or 400 meters.

Update: Nathaniel F. was kind enough to respond to my post (see the comment below), and after looking over the article he referenced and his comments, I think I understand where I (and probably some others) went off the mark. Nathaniel had noted that the 6.8 mm was intended to replace the Mk. 262 round for the Mk. 12 SPR (Special Purpose Rifle). What I think is causing the confusion is that the Mk. 12 was a version of the AR intended to be used by designated marksmen--i.e., more accurate and longer range use of a weapon than expected from a typical Marine or infantryman, but not the range or precision of a sniper; and the Mk. 262 round was a 5.56 mm cartridge intended to provide better accuracy and lethality at ranges out to 700 meters. In other words, that the history related to the designated marksman rifles put into my mind, at least, that we were talking about a round intended for longer ranges than typical engagements.

Nathaniel F. pointed me to a 2006 article by Zak Smith describing the history of the 6.8 mm. Smith's article notes:
The SPC designation was assigned based on the intended integration into the Mk12 Special Purpose Rifle (SPR). The SPC was designed from the ground up to provide increased energy, barrier penetration, and incapacitation from the Mk12 SPR, from contact distance to 500 meters.
In other words, not even the 700 meters of the Mk. 262 round. And, as Nathaniel's article makes clear, inside of the 500 meter range, its performance is not even as good as the Mk. 262.

Anyway, I appreciate Nathaniel clearing this matter up for me.

2 comments:

  1. Hi Docent,

    I never claimed the round was a long-range sniper round. I was very consistent in maintaining that the round was designed to replace the Mk. 262 in the Mk. 12 SPR, which is a matter of historical record. I cite The Black Rifle II by Christoper Bartocci as once source, but another is Zak Smith's history of the round.

    What I question is the configuration of the round in light of the fact that it was designed to replace the Mk. 262. At ranges below 450 meters, the 6.8 SPC does not perform very well in comparison in any respect except energy. I go over all the relevant metrics in the article, but one in particular is its frighteningly short fragmentation range, where Mk. 262 enjoys a 50% advantage(!).

    Cheers,

    -Nathaniel F

    ReplyDelete
    Replies
    1. Thank you for taking time out of your Easter Sunday to reply to my post (especially after the blizzard of comments to your original article). I don't have a copy of Bartocci's book, so I appreciate the link to Zak Smith's article. After looking through your comments, and Zak Smith's article, I think I see where the misunderstanding came up.

      Delete

Paul Joseph Watson: The Truth About The Baltimore Bridge Collapse

In this video, Paul Joseph Watson points out why some of the conspiracy theories concerning the collapse of the Francis Scott Key bridge in ...