Neat info-
The 556 62 grn does not do 3240-more like 2750-2800 from an M4
The 6.8 fails to meet that 2800 fs as well-more like 2450-2500 from a 14 inch M4
Got to compare apples to apples. Remember what I stated in my post-’No free lunches for the Dogs of War”.
It would be nice if the 6.8 actually did perform that well from a 14 inch M4-the truth is not in your quoted table, likely it was derived using a 24 inch barrel or maybe even longer. 10 inches of added length would add approx. 25-40 fs per inch, or 250-400 more velocity than a 14 inch tube. I would not expect any more than my estimated 2450-2500 fs.
Also, given the design of the M4, the point blank figures should be using 14-15 inches above and below the point of aim-the military expects troops to aim center mass and on a standing enemy, that total target height is around 28-30 inces (hips to collar bones)
The M16A2 point plank range is 360 m with M855 ammo (rear sight set at 300+1 click, zeroed at 42 m, then RS backed to 300) Bullet path is approx 15 inches high at 250m, crosses line of sight at 300m and falls below 15” low at approx 360m. M4 5.56 is zeroed in similar fashion, with max PB at around 300m IIRC.
See FM 23-5 M16/A1/A2, M4, M4A1 Rifle Marksmanship for data tables etc. I do not know of any comprehensive M4/6.8 data, just ballistic software figures.
My estimation for the 6.8/M4 is that is would not significantly add PB range, compared to the M855/M4 (again, same platform, different caliber).
Would be interseting to see actual test data.
My estimation for the 6.8/M4 is that is would not significantly add PB range, compared to the M855/M4 (again, same platform, different caliber).
Would be interseting to see actual test data.
Remember that the Soviets, who'd been fielding the AK47 and AKM with a 16-inch barrel since the early 1950s, have also had unhappy users insofar as the smaller bullet of their own downsized 5.45mm AK74- including MikTim Kalishnikov hisself.
What I'd really like to see would be that bullet from the 6.8 SPC utilized in the 5.45mm case, thereby suitable for either the 5.56x45mm-length actions, or the former SovBloc &.62 M43 and 5.45 weapons.... and maybe even the existing magazines. I haven't run the ballistics of the reworked round yet, though I'm sure the Soviets did when they worked out the 5.45 cartridge. But I have offered the idea to someone in that line who's interested.