6.8 spc, its surprising ballistics.

Lets talk about cartridge design for a moment,

new cartridges have popped up here and there over the years but nothing really groundbreaking lots of high velocity hunting style cartridges and a few heavy hitting CQB driven chamberings (.458 socom for instance) and among these cartrdiges is 6.8 spc

Meant as a bridge between intermediate and rifle calibers 6.8 spc has potential but falls flat marketwise

Between 5.56x45mm and 7.62x51mm, 6.8 spc stands trying to be a rifle cartridge, with the size of a intermediate (and the price of a caliber that hasn't been around for 70 years)

Ballistics wise, 6.8 spc is a superior round to 5.56 but it has its flaws as nobody wants to pick it up, and ammunition is expensive, very few companies build parts for rifles in 6.8 and most of them end up just being on the AR platform. because Nato standardized cartridges are cheaper due to their mass production, people want .223/5.56 rifles because they are affordable to shoot. 6.8 spc is seen as "the future of intermediate calibers"


here's a crappy chart (fps/joules are shown with averages)

                                   |     FPS     |     Joules of energy   |   Bullet weight  | Barrel length |
6.8 spc (6.8x43mm)     2570 fps              2,297                  115 grains            16 inch

5.56x45mm  (M855)    2800 fps              1,105                    62 grains            16 inch

7.62x51mm                  2,733 fps             2,733                   147 grains            24 inch


The results are kind of interesting, considering that 6.8 spc can achieve rather decent energy even with the shorter case and out of a 16 inch barrel, would like to buy a longer (20+ inch) barrel to do some testing, but I need to find a set of 6.8 dies first so im not paying out the ass for factory ammo

6.8 spc also gave me some cycling errors, I was shooting it out of a purpose built AR platform rifle and I have on type 4, which was likely a 1 in a million error and a couple of FTE's (failure to eject)

despite this the cartridge is effective on paper, and building a 1 moa or even sub moa rifle for the cartridge isn't hard, i'd love to see a TRUE purpose built rifle (magazines specifically designed for the rifle, and a specific rifle for 6.8 spc that isn't just a AR) I was using PMAG-30 Gen 3's for most of the testing, for .308 I used a M1A1 with standard US GI magazines.